Those proprietary tools mostly run on DOS, Windows XP, and in some cases Windows 7.
That’s a solved issue for the most part, between DOSBox, ReactOS, Bazzite and Linux with WINE. And for the most part, those tools can still run XP in offline mode; they’re never going to be upgraded to a modern OS anyway.
The Canadian government mostly moved to web-based systems a number of years ago anyway; it’s public servant computers that are mostly stuck with Windows — and they don’t need to be.
The bigger challenge is in how to get them off Google Chrome, since there’s a lot of stuff that requires Chrome (as opposed to Chromium) to run properly.