The only good advice I have seen so far was to decrypt system drive, then migrate using Acronis or whatnot, then encrypt it back.
This advice works, except with SSD you could have as well just left your drive unencrypted. Especially, if you have pagefile on system drive, and you probably do, since it is the only way to ensure hibernation works, you have portions of the system memory on your drive, which contains encryption keys, passwords, and all other good stuff. And with SSD, there is no conceivable way to guarantee that it is overwritten.
I am not even saying about the rest of drive contents, which is probably also lurking out there unsecured.
So, the question is: what you do? Have anybody here successfully completed a secure migration of encrypted system drive?
EDIT: This question is about migrating encrypted operating system from drive A to drive B without producing unencrypted copy on either physical drive.