Sorry to say, Mike, they would not accept credit cards or checks (for the accommodations) when I was there. This may have changed so you should check with whomever you make your arrangements. What I did was arrange a bank transfer of the money for the apartment. We brought over about 4000 Euros and we had our bank cards and used them at ATMs for our other cash. The other large expenditure, our car, was paid with a credit card. Most other transactions, e.g. food, souvenirs, fees, etc. were paid in cash. The ATMs are everywhere and we never had a problem.
I am really high of Cretaiole and especially Isabella. She is a remarkable woman, very pleasant, speaks English, Italian, German and French and seems to know how to get anything done. There are daily activities which are totally at the guest's discretion to participate. We did things like a tour of a Winery in Montalcino (The name was Le Prezi and they told us all about Brunello and Rosso di Montalcino) and included an outstanding meal in the cellar next to all the huge barrels, an Olive Oil tasting (Carlo, who is Isabella's husband and appears in pictures on the website with a pony tail, is a licensed Olive Oil Judge and Taster), a tour of a working farm, again with an outstanding meal and a meal at Sant' Ann in Camprena, which was a monastery but is now an Agriturismo. It was also featured in "The English Patient and was the site where he convalesced, if you saw the movie. Like I said, we had a car (Alfa Romeo Turbo Diesel 4 door sedan, which I was upgraded to because they did not have the Fiat I requested!) and we made many trips around the area. It is ideally located, close to Rome, Siena, Florence, Perugia and about 10-15 miles from Montalcino and Montepulciano.
Like I have said here on the forum, if I ever hit the lottery...