4 nights in northern Britanny: where to sleep ?

I stayed one night in Cancale, two in Dinan and a third in Lampaul -Guimiliau (much further west than you're looking at) then went east along the southern coast.

Cancale was convenient for a night between visiting MSM and visiting St. Malo the next morning. Cancale is also famous for it's oysters. It's on the coast. I enjoyed watching the tide change from the terrace of a local restaurant (from boats laying on their sides to boats floating in the water).

St. Malo has nice things to see. I walked the walls but didn't hike out to the fortified islands at low tide (I think kids would love this) or visit the musuem. It also has one of the few sand beaches in the region. I'd shy away from recommending St. Malo mostly because the businesses inside the walls seem wholly dedicated to tourist trade which didn't really appeal to me.

I enjoyed Dinan as a base. I liked wandering the old center. They have a market in one of the parking lots but I can't recall the day of the week. The port area down on the river has several good choices for dining.

I went to the lighthouse on Cap Frehel. It's a great place for bird watchers but I'm not sure I'd recommend it for everyone. The area around Cap Frehel seems pretty sleepy. I did enjoy Ft. La Latte (also on Cap Frehel). It's done service under a lot of guises over the years but now shows as the medieval fortress it once was. The castle was a top sight for me on the north side of Brittany and I think kids would enjoy it.

Have you looked at Dinard? Convenient to St. Malo and Dinan. Great beach. Really fun retro, beachy vibe to the town. Wonderful views across the water to St. Malo.

I think the kids will enjoy Brittany regardless of where you stay. I would think the medieval town center of Dinan would be fun for the kids.

If it is not on your radar, do some internet searches of Locranon. Beautiful, small medieval town. Used for movies sets. I wouldn't suggest you stay in Locranon, but it would be a nice place to visit. It is on many of the "cutest villages in France" lists

St. Malo's parking lots/garages are convenient, but possibly not cheap for multiple days. I would expect to walk to any hotel from the garage, not to drive. I only visited here as a mid-day stop to walk the ramparts, then stayed that night in Cancale and enjoyed watching the tractors bring in the oyster beds/grids. (Rick likes Dinan, which I didn't visit on this last trip, having seen it previously.)

I’d also recommend Dinan. Consider staying at Hotel du Chateau Dinan. They have family rooms, on site parking (€10 per day) and are across from some of the ramparts which kids love. Very family friendly. The hotel is on a Main Street so you don’t have to navigate the medieval center to get there. Just around the corner from the hotel is Le Saint Louis, a wonderful and affordable restaurant. Two great places for crepes are Creperie Ahna and Creperie Art’Billig.

Thanks for those answers !

We decided to saty in Dinan. We have found an appartement that fits our needs, the price is great, 5 minutes walk to the center, private parking. We have chose this place beacause we are not that much into coastal towns. most of the time in summer thsoe places are crowdy by beach people. I guess that there must be alot of people in Dinan too, but not as much...we will see !

Your wariness about road access is wise. We stayed in Dinard in July, so a trip from there to St. Malo for the day involved getting off one peninsula and back onto another, through a road and single traffic-light choke point each way. And in July, this area is plenty busy. I agree that Dinan is over-rated, and the surrounding modern city is much larger than the historic, touristy, mime-and-juggler-filled part.

We slept in a small, family-owned (?) hotel, Reine Hortense, beachfront in Dinard. There was a very nice equipment playground on the sand (maybe national daycare only??) and a sweet little beach cover, with a view of St. Malo. (I don't go on summer vacation to visit beaches, so this was not so important to us.) The rooms were small but modern and attractive. We needed our 240 volt box-fan we'd picked up at a big-box store while driving in our rental car. The private parking for Reine Hortense, nearby, involved un-padlocking and folding down a wicket that made our space un-usable by unauthorized drivers. I thought Dinard had a lot of walking to restaurants if I had tiny child legs. St. Malo is more compact, if far more touristy.

St. Malo is a nightmare of parking outside the walls, the driving isn't that different from any other tourist area.

I just came back from Dinan 3 weeks ago. We stayed in 10 towns across France and Dinan was one of the most memorable. It's actually fairly dead right now so crowds will definitely not be an issue.

Be sure to see the church on Rue du Petit Fort (I believe), it's not on the tourists maps because it's not the main church but it's very interesting inside and out (Basilica Dinan St Malo) . Rue du petit Fort goes down to the Rance river (steep) and it's got tot be one the cutest streets in the world and it's all original medieval. If you have a couple of hours to kill you can cross the Rance on the small bridge and walk south about 1 mile to Lehon, another tiny village. The walk is beautiful. Of course also check out the Dinan Chateau but check the hours because I think it's only open for a 2 hour window.

We tried to drive to Fort la Latte but our navigation took us on country roads and and there was an unbelievable number of road closures/detours so we gave up and went to St Malo instead. If you want to drive to For La Latte make sure you use the highway even though your navi may try to use country roads. I did not find St Malo that interesting as i believe it was all rebuilt after WWII and lacks charm.

It's actually fairly dead right now so crowds will definitely not be an issue.

The OP is going in July so they should be prepared for crowds in Dinan. But I think most of those crowds are day trippers and it shouldn't be too crowded in the mornings and evenings and since the OP is taking day trips from there to elsewhere during the day it likely won't be a problem.