Certaldo Alto is a lovely hilltop town in Tuscany. Not far from San Gimignano but a lot quieter it is a tiny idyllic village with wonderful views and traditional architecture. Not far from Certaldo lies Borgo Petrognano, this venue is surrounded my rolling hills vineyards and olives.
In my opinion, Borgo Petrognano works well for smaller groups. In fact, this couple chose the venue for their small intimate wedding with their friends and family. A simple but beautiful ceremony takes place under a loggia and drinks and refreshments follow by the pool. I take the couple in the countryside for their pictures and when they return they enjoy a romantic dinner on the terrace, cake and dancing.
If you are a small group you could also look at this farmhouse.