Not sure this really falls into what you are looking for, but might give some context for you.
We came thinking we had chosen a part of France where there were few English (being snobbish about it all!) In fact English contacts in the early days were our godsend.
We bought a house that had been a maison secondaire and an English couple acted as gardeners / caretakers for the previous owners. This couple were fantastic in helping us get through those early days. The wife came to the meeting with the notaire, went with us to EDF, Orange, the water company to set up our contracts, explained about CPAM and healthcare and was an enormous help through those early months - I sense there are people on here doing the same in their local communities.
We also were given a flyer by our estate agent about a local “incomers” welcome group in town, which met once a month. Some of the members were from the UK and this group has given us some of our closest / strongest friendships. It was also an invaluable source of general info in the early days, where to go for a good doctor /car service / plumber / etc etc.
Going back 13 years, I also found a large and very active English forum which was invaluable when I had a panic with one of our dogs over a weekend. He had a history of very complicated health issues and in those first weeks I could not have explained all to a French vet, so I was desperate for a vet who spoke English and the forum gave me an answer. She came, on a Sunday, complete with two small boys whom we flung in the pool, and she sorted out our dog (and me, and has been our loved vet ever since).
We also struggled in the early days to find someone to give us French lessons and then bumped into a casual (French) acquaintance in town who recommended the teacher (of English) in her son’s school. I met her for afternoon tea and cake and discovered someone who has a life-long love of the UK, she became not only our French teacher but also a dear friend.
For us, the early days passed so much more easily than they might have done through networks such as this one. I learnt to be less snobby about English contacts and friendships here! I also learnt that help of the most marvellous kind can come from unexpected places, one just has to ask - even in bad French!