As it says on the tin, what's the latest possible date that at least three independent states exist within the OTL borders of France (let's say the 2018 borders) - so no Alsace-Lorraine/Savoy technicalities there.
Is this even possible after 1500 in a meaningful sense? I figure France proper, Aquitaine, and Brittany is probably the easiest way to do this, but I'm not sure it's all that plausible