I would not even consider driving a rental car into NYC.
Are you planning on flying into/out of Newark (EWR)?
Rent a car to drive to Randolf and drop off your luggage.
Turn the car in and ride Amtrak into NYP. Use the subway to get close to the things you want to see in NYC.
There are several trains per day that go from NYP to Buffalo or Niagara Falls. Sleeping on the train saves an expensive hotel room in New York City.
Any desire to go to Boston or other coastal towns?

It's about a 7 hour drive from Randolph, NJ to Niagara Falls and since you'll be going in early October the drive will be very scenic with all the Fall colors. There are some interesting places on the way where you can stop like the Finger Lakes Region, Watkins Glen, the Catskills, Howe Caverns, or perhaps Cooperstown (home to the Baseball Hall of Fame) - and that's just the tip of the iceberg. These stops will add a few miles to your trip but will create wonderful memories. Rochester, NY (about 90 minutes from Niagara fall) has some interesting museums including the George Eastman House Museum (our kids when they were small and now grandkids loved visiting there).

Hint - plot out your driving route on Google Maps then do a few internet searches using topics like "Thing to do INSERT NAME OF TOWN ALONG THAT ROUTE) and you'll find plenty of great ideas.

As an aside, if you have time, the kids (and parents) might enjoy a visit to the Liberty Science Center in Jersey City.

The Statue of Liberty is closed now - but may reopen by the time you get here. Check the web site to see when it will reopen. You should get ferry tickets as far in advance as possible to avoid long waits (even coming from the Jersey side there are waits) and be prepared for the security line to get on the ferry - airline type security) that takes at least 30 minutes.

Oct will be difficult to find low priced hotels in Manhattan - since this is heading into the most popular and expensive time of year. But I have no idea where Randolph is - or how long it will take you to get into the city by train (avoid buses - which can take forever if there is traffic).

No we don't intend to drive in NYC.

I have done this solo before, took NJ transit in Morristown to Penn station, I think that took about an hour. With the kids, I thought it might be easier if we can find somewhere within the NY subway route to stay overnight rather than travelling from my friend's place.

We don't have much choices in terms of flights, more likely to fly in and out from JFK as SQ fly to EWR only with business class, definately way out of our budget.

Thanks for all the replies, appreciate if you would drop any names in Pennsylvania, New York state which you think might be interesting and I will google them.

I hope we will have better luck with fall colours this time round as the last trip to NE, we were a little early.

We raised our kids in PA. This was our favorite- Knobels
http://www.knoebels.com/index.php/rides-a-attractions
If you want something a little farther south try Hershey Park.

What is your budget - and assume you will need a double/double room - 2 double beds.

Manhattan will not be cheap, but you might find some deals on web sites when you get closer (you can;t use Priceline since they only guarantee a room with one deouble bed for 2 people and this configuration is very common in NYC).

If yuo are willing to stay in Long Island City you can be in Manhattan in about 15 minutes by subway. Check the prices there - which should be less than Manhattan - but realize the area is mixed use - some warehouses, auto body repair etc - not a pleasant tourist area with lots of shops and restaurants.

I think your kids will love Niagara Falls. There is a lot of information on this site about Niagara.

There are some good suggestions above. I grew up in NJ and used to live in Singapore and so thinking about what I liked to do when visiting NJ in the fall, I have some thoughts below. You will be there at the height of Halloween madness, so be sure to take advantage of it with kids.

Pumpkin picking – quite sure there is a patch in the Randolph area. Then carve them and bake the pumpkin seeds.

Apple picking – ditto. Then make candied apples.

Sounds like you will be in town for the Far Hills Hunt on October 20. I have not been in about a decade myself, but it is usually a hoot in the glorious countryside. The kids may find it thrilling. http://www.farhillsrace.org/. There are sure to be pumpkin patches and apple dunking going on.

Great Swamp – in Basking Ridge, easy morning trip see http://www.fws.gov/northeast/greatswamp/

George Washington’s Headquarters – in Morristown, also easy half day trip, see http://www.nps.gov/morr/index.htm

Lake Hopatcong – rent boats or just an afternoon with the fall colours, see http://www.morrisparks.org/aspparks/leesmain.asp for info parks there and on all parks in Morris County

Delaware Water Gap – quite a bit closer than Niagara Falls and very lovely; easy day trip from Randolph see http://www.nps.gov/dewa/index.htm. Could include canoeing on the river.

High Point State Park – equally easy day trip, even more rural, see http://www.nj.gov/dep/parksandforests/parks/highpoint.html

American Football game –try the Giants, or a college game (speak to your friends) or West Point see http://www.usma.edu/ (this could be done as part of the tirp up to Niagara Falls)

Boat trip on the Hudson –you can get this from Kingston NY, about an hour from Randolph, and would not involve driving into Manhattan; although you also would not see any of Manhattan, just the lovely foliage of the upper river and some of the “robber baron” mansions like the Vanderbilts (the 1% of the 1880s) See http://www.hudsonrivercruises.com/. Again, this could be done as part of a trip to upstate New York.

Miniature Golf – there has got to be at least one course nearby. Can’t believe this has not caught on in the rest of the world……

Six Flax Great Adventure – amusement park with rides, in Jackson NJ, this would be about 1.5 hours by car, see http://www.sixflags.com/greatAdventure/index.aspx

If you don’t want to go all the way into NYC for a show (or pay those pries) try the Paper Mill Playhouse in Milburn, see http://www.papermill.org/, about a 30-45 minute drive.

Jersey Shore (just like the show!) – if you get a really warm day, drive to Point Pleasant (1.5 hours by car) which has a nice beach and a boardwalk with rides, miniature golf, cotton candy and the whole Jersey shore experience, see at http://www.jenkinsons.com for a place kids will love.

I’d recco the Bronx Zoo, but to someone from Singapore that seems pointless. Coals to Newcastle indeed. But you could consider it, not a bad drive, about an hour, and parking should not be a problem. (Go on a weekday.) See http://www.bronxzoo.com/

For me NYC is a tough call, mostly because you have 2 young children. It’s about half an hour to Morristown, then a little over an hour on the train. So with parking and making sure you get there in time to make the train, etc let’s say 2 hours each way. That’s fine at the beginning of the day when everyone is rested. It’s the reverse that might be tough, esp with the 3-year old. But you know your kids best.

If you are flying in and out of JFK, one thought is to save NYC for the end of the trip and then stay out on Long Island nearer to the airport and go in by the Long Island Rail Road on day trips. Or try Brooklyn, just across the river from Manhattan.

Or try hotwire and other booking sites and see what you can get in Manhattan for your dates. You may luck out and get a good deal.

Wow, thanks for the recommendations and details.

Honestly, somehow I have not thought about leaving NYC till end of trip. I should definately consider that since it is definately better than doing day trips.

BTW, I usually use Agoda for booking Asian hotels, please advise what other websites besides those that had already been mentioned.

I think the main area for farm stays is in the Lancaster, PA region, a little bit too far south of your route to Niagara Falls. You can tour the Amish farms in the area and also visit Hershey Park, an amusement park built by the Hershey Chocolate company.

The drive to Niagara takes you past the Finger Lakes, which have beautiful views and scenery, especially in October when the leaves are changing. In Ithaca, for example the campus of Cornell University is split by gorges and waterfalls which are overlooked by pedestrian suspension bridges. Geneve, Seneca Falls, and Skaneateles are nice small towns to poke around in.

A google search turns up several farm-stay and B&B's near Ithaca, but I have no personal recommendation.

Are you allowed to exit and re-enter the US during your stay? If not, you can't go to the Canadian side of Niagara Falls -- a shame, because some of the best views are from the Canadian side.

We went from US into Prince Rupert to board the Alaskan Marine Highway in 2005 and managed to fly back into SFO after the trip.
Singapore was already on the VWP and I hope my memory/geographical knowledge is not that bad but PR should be in Canada.
My understanding is that as long as we are less than 90 days into total, we should be allowed back in. I just need to ensure that the rental car is allowed into Canada.

I just realised that we should be arriving the weekend before Columbus holiday. Any interesting parades within a couple of hours' drive that we should be at? (I'm assuming the parades will be on Monday itself and take into consideration we would have only arrived on Saturday.)