Saint Malo

If you want a "local lifestyle", avoid Intra-Muros, the very touristy area inside the city walls. Saint-Servan would be lovely, and equally accessible by public transport if that's what you need. If you have a car, road access to Saint-Servan is easy... and you actually have more options. With a car, you could choose to stay across the estuary in Dinard (fancy resort town), Saint-Lunaire or Saint-Briac (more family-oriented, quieter). In such a case, a day trip to Saint-Malo is more than enough!

https://community.ricksteves.com/travel-forum/france/help-with-brittany-itinerary

In the first place I would follow the advice of balso. Think it was 2016 I had a picnic at the border of the Baye of Rothéneuf, Le Havre de Rothéneuf halfway between Saint-Malo and Cancale. In between the area has not so much changed. Very pleasant atmosphere, but I have no experience staying there as I stayed near Dinan (that's not Dinard!). Places along the border of La Rance estuary south of Saint-Malo like Saint-Suliac and Mordreuc are lovely too.

Think there is a bus service between Rothéneuf and Saint-Malo but for the other places travelling with the bus will be difficult I guess.

Thank you all for the advice. We are staying in the area for 1 week, no car - maybe for a day or 2 local rental and hopefully renting ebikes for day trips - on our list at the moment we have:
Explore San Malo
Trips to Dinan, Dinard and Cancale
Day trip to Jersey
Get a car and see Barfleur and stay overnight in MSM ( might have to double book accom for that night)
When we leave we are looking at taking the ferry across to Plymouth

Any further suggestions for destinations and how to get around?

additional links:

https://community.ricksteves.com/travel-forum/france/normandy-brittany-thoughts

https://community.ricksteves.com/travel-forum/general-europe/london-normandy-paris-help-with-itinerary-transport-options

Why not get the ferry to Jersey from St Malo, stay the night and then go on to the Uk from there? Barfleur is lovely, was there last spring, but dont think I would do a day trip of that length for it? MSM - stay the night on the mount.

My first thought was the same as caro's. I like both Jersey and Guernsey, and I think it would besmart to make at least a one-night stop on one of those islands on the way to the UK.

I will warn you that it isn't unheard of for one of those big Channel ferries to be canceled. Keep your eye on that; you might get a notification from the ferry company, so monitor your email as well as text messages (depending on what contact info you've provided).

It is the same with any travel.
Have been delaye more often in airports due to techical problems, fog or snow than i ever have at a port and I use ferries alot as I live in Guernsey. Delayed once in the Caribean because of snow in Gatwick for 10 days!!!! Not good.....Ferries are my first choice of travel these days, alot more relaxing.
Have alovely trip, it is a beautiful part of Brittany

I would want to be within the walls and hang the 'local lifestyle' -- we had an apartment steps from the wall and entry to te beach and it was a delight to walk out for bread in the morning (there are 3 or 4 bakeries intramuros) and then come back 'home' along the wall with the great views out to the sea. There are stunningly good restaurants (and some tourist junk) and easy access to walk into St. Servan and the Tour Solidor or wander on up the coast. St. Malo is gorgeous and most so in the old quarter.

There are buses to towns in the region from the train station which is a short bus ride from the walls.

Thank you everyone! Great insights!

Stay where you can see the tides. If you love the sea, they are fascinating. In St Malo, many quaint hotels line the waterfront.

the tides are amazing and they have a power plant at the mouth of the river that is run by the tidal surge. Boats are fitted with outrigger stands so they rest on the seabed when the tide goes out. All quite stunning.

WE arrived when the tide was in. Could see the diving board of the beach 'pool' sticking up out of the water and islands. The next morning when I was returning with bread for breakfast, the tide was out and people were walking to the islands. I rushed back to the apartment and dropped the bread while my husband slept and walked out to the islands following the crowd -- amazing stuff. I had never seen tides like those.