|My comfortable minivan with AC|
|Photo from my Val d'Orcia photography tour|
Italy is about the size of Arizona, so compared to the states it's tiny. Tuscany is only a twentieth of Italy, so it's easy to be mislead into thinking it can be seen in a day. However it's still 8,900 square miles, which is much the same as new Jersey. Another mistake that can be made when considering travel times, is assuming there are fast road connections. With few exceptions roads are busy if not very busy, and most of the places you will want to see are on winding country roads. Your driver can probably drive them like the Indianapolis 500, but you won't thank him if he does. Ask your driver to advise you on travel times.
And finally...when proposing a tour, your guide has used his knowledge and experience to give you the best in terms of sites and activities, and he will have optimized times. Read the tour description carefully and ask yourself if you really need to make variations? If you do that's fine, but ask for custom Tuscan tour.
Last minute requests may give your guide problems that he may not be able to deal with on short notice. Give him as much up front information possible, and put him in the condition to give you a great day.