In theory they could. Every city or state that migrates increases the market for open source solutions, and many also invest in the creation of custom software that others can later use when they migrate. The problem imo is hitting a critical mass, and also overcoming lobbyism at the highest levels.
I don't think so. Our gendarmerie is running a Linux distro since 10ish years, but the National Police is planning to change all the computers for windows 11. They are doing almost the same thing but there is a painful difference in Microsoft's ass licking
I dunno, between how clearly French people routinely and thoroughly let it be known that they will not be fucked with by their leadership and shit like this, if I win the lottery and get rich enough for some country to let me escape from the white nationalist oligarchy of the US, France is looking pretty good.