We plan on spending 4 days near Carnac stones. Looking for a place to stay with a party of 7 3 of which are teens and preteens. Also other areas that might prove interesting.
We (my daughter, teen granddaughter, tween grandson) stayed in Vannes and thought it was a great location for exploring that part of Brittany. It is a charming town in its own right, with an interesting medieval section inside remparts. We spent one day on the Quiberon peninsula and saw many, many megaliths; I was surprised that there were acres of them!
I don't have any recommendations as to where to stay with 7 people, but when I was researching for us, there were many places on airbnb, through which we rented the apartment. We were there this past June and traffic was not a problem on the peninsula or elsewhere;I imagine it is different in high season.