usual good stuff from Sandra,

OP don't just grab for your go-to solution of a car, for a lot of places you will want to go to the train actually makes a lot of sense. After some 10 visits to Italy I've only used a car twice and once for only 24 hours. Certain places benefit from a car, so Dolomites would be one.

Google map times always seem over optimistic, certainly they were on our two car trips.

Thank you, everyone, for all the great ideas and information. We have changed our itinerary, though, to fly home from Rome instead of Turino. Since this invalidates lots of the above suggestions, I think the best idea will be to start a new thread.

FYI, We are now planning to leave Venice on May 8 after 6 nights, followed by two nights in Verona, two in Milan, three in Mereggio, two somewhere between Mereggio and Volterra (Bologna?), two in Volterra, ending with four in Rome (we've been to Rome several times so four is OK.) Lots of moving, I know, but we're up for a road trip this time. We will have a car most of the time.

Nothing except Venice and Rome are in stone, though, so still open to any suggestions, especially on where to stay in these new spots.
Thank you...and hope to see you on the new thread!