It’s a 4 hour drive plus pit stops, almost entirely on 4 to 8 lane freeways.
I would stop for lunch at one of the many rest stops on the freeway at an Autogrill restaurant, that way you don’t need to exit the freeway system. By the time you are done and drive the rest of the way it’s time to check in.
The drive is mostly a boring flat plain up to Bologna. Then the freeway goes underground under the Appennines mountain range in some of the longest tunnels you’ve ever seen. The Tuscan part is a bit more interesting. Once you exit the freeway at VALDICHIANA, after Arezzo, right near the exit there are the outlets of Foiano, if you want to do some shopping, before taking the road up to Montepulciano.