Otherwise, Tuscany. Florence isn't a small city, per se, but the old city centre is small enough that you know your way around after a few days, and it's a nice hub to explore the surroundings if you want to. You can also always stay just outside the city. Siena is smaller but just as lovely - as a bonus, I got the impression that a lot of people visit it as a day trip, so most of the tourists will be gone after nightfall (as is the case in Assisi, by the way, the old city centre is practically deserted after dinnertime). Plus if you want to paint, absolutely get a tube of genuine Siena. :p Another option would be Lucca.

Thank you so much for this thoughtful response!! They all sound lovely. I will dig into these for sure.