Can't speak for France but in Germany, you can usually check on each ISP's website what their coverage for a specific street address is. It's one of the things I always do when I look for a new home.
The information is available publicly on the same web site as mentioned in this thread, with even information about the expected network throughput: https://maconnexioninternet.arcep.fr/?lat=46&lng=2.3&zoom=7&...