Entirely too ambitious. NZ looks small on a map, but it takes longer to get from point A to point B than you might expect. Roads are narrow and winding, generally one lane in each direction and there are many one lane bridges. It can be slow going under the best of circumstances, much more so if you get caught behind a campervan or truck. I suggest you take a look at drive times/distances here:

http://www.aatravel.co.nz/main/td-calculator.php

Regarding Thurs 15 Nov-Mon 19 Nov

Milford is a four hour drive from QT in the opposite direction of Wanaka

You can combine Wanaka and Mt Cook on your way to Christchurch (Lake Tekapo too), but not the glaciers. These routes are separated by a mountain range. You'll have to choose one or the other, particularly with so little time.

Hanmer Springs is about 90 minutes north of Christchurch and Golden Bay is about a five hour drive from Hanmer Springs.

The ferry from south to north leaves from Picton and ends up in Wellington. You can also fly...perhaps from Nelson, but keep in mind that Golden Bay is about a 90 minute drive from Nelson.

I suggest you stick to one island or decide what you want to see the most and fly between islands.

Melnq8 has a great deal of experience, so I will just confirm that your best bet is to fly between the islands in both directions, you will otherwise be very rushed trying to get back to Auckland.

- consider flying onward to Queenstown after you arrive in Auckland, it's not that much further on and will consolidate your time. Consider doing Queenstown, then heading off to see the glaciers for a couple of nights, and then double back to Queenstown for one last night and fly out of Queenstown to Auckland. You can do a second loop out of Auckland to link together your North Island destinations.

We got a campervan and drove from north island (Auckland) to south island (via Ferry between Wellington and Picton)and flew back to Auckland from Christchurch. Hindsight, we should have just spent more time in Queenstown or visited the glaciers and flew back to Auckland from there.

I would recommend taking the air tour to Milford Sound. The views of the mountains and glacier lakes are amazing and flying over the sound out to the open sea is a great experience, not to mention you're saving a lot of time.

There's an offroading tour that takes you to Arrowtown. It's a great tour and you get to ford the river and visit old mining towns. The scenery is beautiful.

Don't miss Ferg Burger in Queenstown. It's one of the best burger I've ever had anywhere in the world! We ate at a fancy seafood restaurant by the wharf. It was good but not great especially since the price was really up there.

Riding the Jetboat (Shotover) is also a must do in Queenstown. It's really fast and amazing. Please be warned that because of the high speeds it gets really cold. Having gloves would help as you hang on the cold rail for dear life

As previously mentioned, you might not have time to do everything on your current itinerary. We wanted to visit the glaciers as well but the drive time from Queenstown was too long.

The Waitomo Cave is a pretty unique experience and was our first stop in the North Island. Yahoo Travel named Waitomo Glowworm Cave one of the ten best places to explore the underworld.

Don't miss the luge in Rotorua. They have this also in Queenstown but we enjoyed the Rotorua runs much better.

Dear all, thanks so much for your replies...

Can I do the following:

15th Nov morning - arrive Queenstown
16th Nov afternoon - drive to te anau (spend night)
17th Nov morning - head to milford sound
17th Nov evening - head to Franz Joseph after Milford Sound experience (spend night)
18th Nov morning - experience Franz Joseph
18th Nov evening - fly to auckland from Hokitika airport

Or, is the below better?
15th Nov morning - Arrive Christchurch
15th Nov - Head to Franz Joseph (spend night)
16th Nov morning - experience Franz Joseph and head to milford sound (spend night)
17th Nov - Milford Sound cruise; head to Queenstown (spend night)
18th Nov - spend in Queenstown; depart for Auckland at night?

I know we're really short on time but still want to experience as much as we can....

Milford to Franz Josef is an 8.5 hour drive and not something you'd want to do at night, as you'd miss all the scenery.

Franz Josef to Milford is also a 8.5 hour drive, so both itineraries have the same issue.

How about arrive Christchurch, drive to glaciers, drive to Te Anau, breaking up the drive overnight in Wanaka, then returning to QT after Milford to fly out from there? I think you're still short on days though, so it's going to be a stretch.

Thanks Melnq8 - given the time restraint what you've suggested does seem like the best option.

Will it be easy to get a car rental/coach to take us to the glaciers or should we book in advance? I'm assuming we should be able to get hotel bookings quite easily through the i-site centres, or so I hope.