I have hired a private driver to take us from Florence to Rome and have the driver a total of 8 hours. We plan on visiting Orvieto but would like suggestions whether we have enough time to visit a second town as well. If so, where would you recommend.
Siena comes to mind. You can drive the Chianti road from Florence to Siena. Also Montepulciano is not far off the A1. A lovely hilltown.
You could easily spend your time in Orvieto. There's a lot to see there if you take in the Etruscan sites as well as the duomo and several of the shops. I'm afraid if you include a second town, you won't do either one justice.
With only 8 hours total, I wouldn't add Siena as it needs a full day at least. I agree you'll be hard pressed to fit more than one in accounting for travel time, traffic and lunch. But a smaller town that you can just walk around for an hour might work. Others will have to suggest one or two.
for a reference to a great sandwich in Greve and S222 wine tasting see
http://www.ricksteves.com/graffiti/helpline/index.cfm?topic=48747
I like the idea of being able to visit a small town for an hour but still leave most of the time for Orvieto. Greve sounds great but I see it's very close to Florence and as we'll be leaving there by 8:30 a.m., I'm assuming it's a bit too early to visit and therefore would have to look for a town closer to Orvieto. It sounds like the 222 would be a good road to drive down which is helpful as we'd rather not drive down an autostrada. Any other suggestions on roads to take or small town to visit for an hour is greatly appreciated.