Agree with Souphie on Roellinger, stay at the old family home not the fussy new place and eat at the fussy restaurant. Your room faces Mt. St. Michel and for breakfast as l did, you can go to town get wonderful oysters and shuck them in your private outside terrace. Another oyster bar in St Malo, three dozen each and two bottles of muscadet cost @ 60e last year. When you go from St Malo to Mt St Michel take the back road through Cancale rather than the autoroute, much slower but that is why you are there
One of the best nights/days in my life.
If you go to Pont Aven, restaurant called Le Taupiniere; while the langoustes were perfect, the true memory is of the owner and wife treating us like family, even letting me cook with him in his kitchen. That memory is one of the reasons l love France so much.
Try to get to La Guerande for the salt, sounds trite, but arguably best salt in world, and seeing the process for me was fabulous, my new dog was named 'paludier' after the trip
Even with a car, Brittany is awfully large, easily three hour drive from one end to the other. Care to be more specific about the location?
Best restaurants in Brittany are Roellinger in Cancale, Abadie in Lorient, Carantec by Morlaix, Thorel in La Roche-Bernard, Hotel de la Plage in Sainte-Anne. Random creperies and seafood are often wonderful.