imo there is no easy answer for Windows 10 upgrade
If it were me, i would not try to upgrade but rather start with a fresh install or better yet a new computer with windows 10 already installed.
Right. I'm not thinking of UPGRADING the observatory PC from Win 7 to 10. I would buy a different PC with Win 10 Pro already installed, and move all my drivers and apps to that.
Regarding updates and internet access, imo it seems an unfortunate situation that constantly updated software and OS is where we are headed, which has both good and bad consequences.
That's a real shame. I really don't like software vendors assuming everyone has unlimited Internet speed and data. I live in a rural Virginia county, and get Internet via a 4G cell tower. We don't stream anything, and can't join a Zoom call because of the limited speed and data. But I have fairly dark skies. :-)