As much as I disagree with your last statement (I think Linux for client is on par with Windows for the vast majority of users), I strongly agree with everything else. This wasn’t a Windows problem, but a “your IT is cockblocking you” problem, it could have happened in Linux too if it wasn’t because he used a rogue device, he could have fixed it on Windows too doing the same.
Personally I would have gone straight to Linux because I’m out of the loop on how to do these sort of stuff on Windows. If it had to be Windows, let IT figure that out, their firewall, their anti-virus, their problem.
You don’t need to port the home directory, just have it stay on the other disk, that’s how I used to do my systems when I had small SSDs. But porting it should be straightforward, just copy it over and it should all work.