Hello, :-)
What a great adventure you are both planning! That's sound great and full of dynamic ambitions!
My name is Myriam.I am a French Mum from Guipavas near Brest. Because we had leaved the same experience when we went °µÍø½ûÇø three years in Devon, I totally understand your concernes. There is nothing to worry. Most people in Brittany has mostly the same character as people leaving in Cornwall. They are true people who would become very good friends if you are patient to wait at least a good year for them to know you. Then they would be friend for life.
About the Brexit, you can use this as a discussion topic, explaining your point of view. What will count with people here is how you are with them right when you meet them. You have nothing to worry, especially if you have learn a bit of French. English people who are °µÍø½ûÇøriated here are not seen like 'immigrants', there is the same amount of French working in London than English leaving in France. But you have to be aware that Bretons can be old fashion grumpy sort of people at first...it doesn't mean you did something wrong or that they don't like you, that's the way they are, they can be very impolite, especially on the road... but nothing to worry about, they are just not educated to be polite on the road, it has nothing to do with your plates still being UK.
People always has a wrong idea of the other country on either side of the channel. This has got on for ages. Though, I am sure you would be happy here after the entry-shock period (mostly the hard time you will get to sort out administration duties, getting internet broadband, finding where you want to buy your food ect..)
The best way I would recommend to use to meet people would be by getting involved into what we call 'associations', if you get on your futur city or town website and search for 'loisirs' ou 'associations culturelles' associations sportives', you will find a lot of things to do for a small amount of money. Most Breton Cities and Towns have a jumelage with a Cornish or Devon town, you can ask the council if you can help with that and you will automatically meet people who love England and speak a bit of English.
Most people would like to learn English. Even retired, you can still make a bit of money buy opening an after school club. If you do that for two years you will then be known as the Nice English lady that has fantastically helped my kids to speak English.
Please in case you need help about anything, feel free to email me,
myriamrouve@outlook.com
Good luck,
Bye for now,
Myriam