If I may just add a comment.
Solidfunk start simply implementing the new regions (as they are the official ones!), I think this will already add lot of work.
I don’t know how you’ll do that but the easiest is to use postal codes that are on Brewery address. This code with 5 digits starts with 2 numbers that reflects departement index, as showed in the map provided by Vincent.
So for example, brewery with 66xxx is part or “Pyrenées Orentiales” department, so included in Occitanie.
Anyway if I (we) could help you on that tell us.
I can provide you the complete map between the 2 digits and the Region’s name.
Vincent : overseas departments are of course in France but seen as different in “culture” so separated as different beers countries. I had this discussion lot of time with admins in the past as I wanted them unified, I finally agreed with this - moreover this allows us to have more countries rated ! Anyway there is no “cabbale” in ratebeer to limit France area