Siena

I should have clarified that I want a 2 or 3 day stay and I think you have to stay a week there. Am I correct?

Here's another suggestion that allows two or three day stays:

http://www.mulinodiquercegrossa.it/sito/en

I've got just the place! We stayed at Agriturismo Marciano in September for 4 days & we loved it. It's only 10 minutes from Siena's walls. The rooms are very lovely, clean & comfortable. The atmosphere is very relaxing. It is a working organic olive grove & vineyard. They offer the opportunity to dine in several days/week & the food is to die for (and they pair their homemade wines with each course). We ate dinner there twice & they were the best meals of our entire trip. The rate includes a nice breakfast around the farmhouse table. We really enjoyed meeting the other guests there & the owners are very friendly & helpful. The rates are really decent considering what a wonderful experience you will have. Have a wonderful trip.

I just made a post on my blog of a few - Casa al Vento is near Siena (Gaiole) - not next door, but close. It is a great property and they have rooms available by the night:

Agriturismo in Tuscany