Encrypting the Ubuntu partition with a Windows dual-boot

The Ubuntu installer offers to encrypt your disk while installing, but this option is not available if you're dual booting with Windows or whatever else.

An unencrypted OS installation basically means a fully accessible computer with zero security. And the dual boot is an extremely common situation for linux laptop users, so it's really important to find a workaround.

In this blog post I wrote down all I had to do to make this work on an HP Omen laptop, which gives you extra hard time. It required half a dozen different stackexchange-inspired solutions used together.

I've looked around for encrypting both Ubuntu and Windows on the same disk, and haven't found anything. After playing around with it a bit the other day, I think it's possible.

Has anyone done this or know of a guide?

Bonus points for 2 Ubuntu installations and 2 Windows installations.