I did an install of Windows 10 Pro N on a Mac Pro a couple weeks ago (followed this guide:
https://forums.macrumors.com/threads/opencore-on-the-mac-pro..., search for "Installing Windows and Linux " section).
The Mac was connected to the Internet, I had to do a couple of clicks during the setup to create a local account but it was easy enough to do - I had not searched beforehand and I hadn't set up a Windows machine in the last five years or so.
Side note for fellow people willing to run W10 on Mac Pro's, two things: the multi-socket variants won't run on the Home edition, you need the Professional edition, and if you're using Opencore you will need to enable the OpenShell EFI shell as you'll need to run bootmgfw.efi once from the UEFI shell.