We’ve used quite a few Chambre d’Hôte and small owner run hotels all round the country, the standard is generally quite high (especially for the price) and its not uncommon to be able to book an evening meal. I suppose one angle OP might be to pick a spot popular with Brits and leverage that for bookings. Obvious question is how is your French ? Will be essential for French clients and dealing with the bureaucracy. I suppose the other comment is it’s a decent lifestyle business if you don’t need the money. Holiday lets are fairly common too, oldsr country houses with oitbuildings which have been converted into summer lets, again decent pocket money rather than a living I would say.
As for Brexit I personally foresee zero problems for Brits relocating to France spending money on property amd paying local taxes. They need that.
Anyway good luck, keep us posted. We love Spekie’s thread