- Debian/Devuan/Gnuinos users with offline DVD's ISOs mirrored under an USB drive: easy mode.
Most of the docs are already there, just mount the ISO's as a loopback device and run apt-cdrom add against the mount points.
- Windows user: hell.
Ubuntu/Arch/any distro without full ofline mirrors: hell too.
a true test for a progammer is to see what they can do on a computer without the Internet.