I think that based on the activities you like, you should consider a smaller inn or B&B in a Tuscan town, as opposed to a full blown resort that is self-contained and not within walking distance of a town/village. That way you can relax on the terrace, or be out at a restaurant, sitting at a caffe, riding a bike, or whatever else. I like Perche's suggestion of Montepulciano and Siena. You might also like San Gimignano. My advice when wanting to be outside of the city is to research a town that seems interesting to you, then try to find accommodations. If you decide on a town, maybe I can help find someplace to stay.

As far as Florence goes, if you don't have that planned, I can be more helpful with that. I make it there once a year and can give you some specific guidance.

Don't make it make it more difficult than it needs to be. No matter what, you are going to have an unforgettable time. I mentioned Siena, San Gimignano, Montepulciano, and you said you wanted something rural, not within a city.

You really need to choose an area of Tuscany where you want to be. It sounds like you want something rural, but not too far from a town or a city. That suggest that you want a B&B, or an agriturismo where meals are provided, or you can drive and get meals.

You didn't like Lupaia just outside of Montepulciano, with killer views of it. I think you wanted something not as upscale, there are a lot of others around there to consider.

Agriturismo San Gallo and Poggio Etruscan are just outside of Montepulciano, and are considerably less than your budget.

Agriturismo Malafrasca is in the Chianti hills less than a mile outside of Siena. Hotel Le Fontanelle is big enough to have weddings, but is rural, 10 miles fro Siena, is not a gated resort like Il Burro. It's kind of in the middle of nowhere, though. Fattoria il Poderaccio is an agriturismo about five miles from Siena.

Borgo di Pietrafitta Relais is right in the center of Chianti region, very rural, 15 miles from Siena, but only 2-3 miles from the typical Tuscan village of Castellini in Chianti. Small, rural, not touristy, big enough village to have some nice restaurants. You should take a close look at this one.

Agriturismo Cretaiole is just outside of the quaint town of Pienza, down in the Val D'Orcia, the typical rolling hills Tuscan countryside. Agriturismo Il Colombaiolo is in the countryside but just a five minute walk to Pienza.

Casanova di Pescille Farm House is just a mile outside of the wonderful town of San Gimignano.

Google these, and see if any seem to your liking.

I had a rep from the Lungarno Collection in yesterday and she has a new Tuscany property - Monteverdi that looked interesting. They have cooking lessons, small property and nice views. I only had a quick overview but might be of interest to you

These are all great suggestions - thank you! Researching all of these options now.

My partner and I are also staying in Florence on SPG points at the Westin Excelsior for four nights in late April and then spending the rest of two weeks around Tuscany. We're spending five nights at Agriturismo Il Castagno (800 Euros total) just outside of Siena and three nights at Azienda Agricola Fabbrica Di San Martino (3 nights at 459 Euros total) outside of Lucca. Both are small, look beautiful, and have their own olive oil and wine production facilities. Dining at Il Castagno is reportedly fantastic!

We'll take a bus from Florence to Siena and rent a car in Siena. (I didn't want to drive a rental car in, around, and out of Florence!).

So, I actually stayed at Il Borro 10 years ago. I rented an apartment in the village for a few nights. While it is was a lovely trip, it is very isolated from Tuscany and town. You definitely need a car.

I also stayed at Terre di Nano, an agriturismo right outside Montepulciano.
Very relaxing but not too far from town. We took several days trips - the Abbey of Monte Oliveto; Deruta. Would highly recommend it.

http://www.terredinano.com/index.asp?lang=eng

Terre di Nano looks great. It's not a gated community like Il Borro that isolates you, and yet looks to be 1 five minute drive to Montepulciano and maybe a 15 minute drive to Pienza. It seems that this would be another great relaxing place to stay, and as a base for exploring the Tuscan countryside.