I am sketching out a 2 week trip in Italy next July with my wife and 2 teenage daughters. For a the Tuscany/Umbria portion of the trip we are planning to rent a car. Right now I am thinking that after 2 days of relaxation in the Cinque Terre, we will rent a car in La Spezia and drive to Sienna with stops along the way in Pisa and San Gimignano. We want to spend a night in Sienna, and then spend the next day driving through the Tuscan countryside. I would like to spend the next night at an agriturismo somewhere between Sienna and Orvieto, especially one with one of those long outdoor farm meals I keep reading about. The next morning, we will turn in our car in Orvieto and continue on to Rome by train.
Does this itinerary seem realistic or am I trying to pack too much into 2 days with a car? Are there any good agriturismo recommendations near Orvieto and do these places accept single-night visitors? Thanks in advance for any help...it's a little overwhelming!