I once tried flying EWR-HKG with a CO 777, but when I got near, I think it was 86th parallel, ATC just abruptly cancelled my IFR flight plan. I was right on track and at the correct altitude.
Is it possible to fly the polar route?
Trying to fly over the poles in MSFS is a practical impossibility it seems
If you set a particular heading, fly it, and then use wing leveller (so mag forces do not affect the course), you'll find when you get to the north pole it seems to just go round & round, unable to get to the other side.
Another thing, there are some beautiful auroras/winter lights up there