New desktop migration process:

• Nuke Windows from new desktop.
• Install Ubuntu and all the software you can remember needing.
• Create a single encrypted partition on the spinning disk. Easy to do now in the Disks app.
• Pull that disk out, and migrate data from existing desktop encrypted drive to it.
• Put the drive back in the new machine.
• Create all required symlinks so that everything sensitive is on the encrypted drive, but the system drive is clean.
• Start work, and fix everything that's broken, install missing things, etc. as you go.