Cash payment in Provence

How many days are you speaking of? One week, two weeks? Do you have any limits or expectations about costs? What is your lodging budget or maximum? How did you do your lodgings booking...with the location itself, with Booking.com, with another booking site? What tours did you booked and where did you find them, Trip Advisor, perhaps? If you provide the name of the tour company/group, they may be known to some of the forum members.
We have booked with Booking.com, Gites-de-France, the lodging itself. We haven't ever paid it all in advance except for a very large place in the Dordogne for 7 people, through Gites-der-France, but the balance wasn't due until about a week or two before our time there. Of course, I have confidence in Gites-de-France, as well as Booking.com. Never had a problem with either, even when we had to cancel (within the cancellable time, of course).
I don't know about the wine tour group as we always do this sort of thing on our own, having a car.

The wonderful b&b I stayed at in Arles only took cash and did not ask for a credit card to secure the reservation. I had the same concern beforehand as you express but I was reassured by email correspondence and everything worked out fine. I paid the day I was leaving. I appreciated that the host even suggested where to find a nearby atm connected to a bank if I preferred that (which I did) to a freestanding atm.

Sometimes the smaller businesses like to do things the old fashioned way. The Hotel Diana in Paris that was sold in a couple years ago never took a credit card or deposit.

I would suggest contacting your hotel and tour company about a week prior to your visit to reconfirm your dates and provide your contact information.