Interesting but I'm not sure I'm buying it ;-)
Radisson is a small unconstituted locality so whether it qualifies as a town is questionable.
It also has a population small enough to fit in two or three buses.
It is predominantly French speaking, is 1° further north than Dunkirk, is incorporated as Ville de Fermont, has a population of about 2400.
It also has a Wikipedia page that claims "Fermont is arguably the world's northernmost Francophone settlement of any considerable size": https://en.wikipedia.org/wiki/Fermont.