Here is my plan. Please tell me if it is practical because I really need to firm up hotels.

Already have reservations to fly Nice to Rome (blu). Thank you kismet for suggestion. Take train to Orvieto, - how long does this take - spend the night (Hotel Duomo is good?), next afternoon rent car and drive to Siena and overnight, then Montacino/ SanG, (should I use one or two nights?, then head back to Orvieto to return car. I will then take train to Rome to use remains two nights in Rome before my Sept. 14 flight home.

Does this make sense? I can't tell driving distances.

I just think walking all around Rome for 6 days will be too hard for my husband.

my best advise...stay at least 3 nights anywhere you go.

I completely and deeply agree: at lest 3 nights anywhere you go is a very wise advice.
It is the time good enough to begin to feel yourself, in a delicious small town, a temorary citizen rather than a fast tourist.

Vincenzo

If I wish to visit the other towns, which is most central considering I am going from the Rome airport perhaps mid afternoon. Should I get a train north or rent an auto. I truly wish I had a month to visit Italy. Fortunately I had a lovely long tour a few years ago which allowed me to see at least the highlights of Italy.

I suggest renting your car at the Rome airport and driving to one base (either Montalcino, San G or Siena- all are within 30 minutes or so of each other), stay for 3-4 nights at the one base and explore the area. Then drive to Orvieto, explore the town, drop the rental car there and train from Orvieto into Rome for your final 2 nights.

Consider staying at an agriturismo while in the countryside. It is a very relaxing contrast to Rome.

The train from Orvieto to Rome is about a 1 hour ride.

Also, here is some great information on driving/parking in Italy-

http://www.slowtrav.com/italy/driving/index.htm

I really like zoecata's plan. That's what I would do. Only exception is I wouldn't stay in Siena with a car. Parking is difficult and the roads around Siena can be a bit confusing. The smaller towns like SG and Montalcino/Pienza/Montepulciano are much easier for in/out for day trips. I kind of like southern Tuscany more.

Buon viaggio!

In Orvieto, we stayed at Palazzo Piccolomini and liked it. It's at the opposite end of town from the train station. Orvieto is a very walkable town!

Agree with zoecat's plan. You can find out driving distances at www.mappy.com or on a paper map of Italy. None of the distances mentioned here is very far at all.

We have settled on Montalcino and found a lovely B&B. I asked owner for info on getting there from Rome. Do you all have any suggestions. We will rent a car, but should we rent in Rome or...? Our flight gets in from Nice at 13:50. I'll never get used to those times (I have a son-in-law in military too!) I think it is 1:50 afternoon. Now the hard part - getting back to Rome and finding a hotel that is charming, near public transportation, at a reasonable price $125 euros max). I figure I will have eaten and drank all my money away. You might see this on my other post, so be patient with me.

Did you read the responses above? Rent at the Rome airport. Return car in Orvieto and train into Rome from there. The link I posted 3 posts above your last post has lots of helpful information.

I suggest you purchase (prior to your trip) a map of Tuscany with a 1 : 2000 000 (1 cm = 2 km) ratio. Using your guidebooks and the map, you can then plot out your drives for each day.