Please book as far in advance as possible, the region is very popular summer & fall. We are looking into complementary transportation from Montepulciano for the wedding day.
Montepulciano has boutique hotels and Airbnbs, because you're inside the hill town walls, you won't find any pools. The streets are cobblestone and hilly so may not be ideal for some. In the country, you'll find Agriturismos, which are working farms that have been renovated into guest houses, typical of Tuscany, Umbria, and Sicily. They range from simple to luxurious, most have pools & gardens. Regardless of where you book, you'll likely want A/C (or very thick country walls & fans) as it could be hot.