We found Le Bois Coudrais campsite by chance online while searching for best campsites in Brittany.
It is an intimate campsite of around 25 pitches with lot of space. The restroom, showers and washing area were always clean. Swimming pool is lovely and great when you have kids and Claire and Philippe are lovely hosts, always smiling and helpful. They run a small shop/cafe which we used a few times :)
Also, the campsite is very well situated if you intend to go to the beach (St-Malo) and then visit inland Brittany, like Rennes, Dinan, etc.
We will totally go back next year hopefully!