I have a script that can setup a bootable partitioned usb drive, set it up to be encrypted, then dd/rsync all my system and data files to it.
I keep a couple of these bootable-backups around, one of them off-site.
I can connect the usb drive to another pc and boot my system up on it. If I need to I can run the script and have it copy everything from the usb drive to the new pc internal drive.
This system has served me well for a number of years, and a number of computers.
I'm running Freebsd and I use GEOM for encryption. I did do a new system install to go from 32 bit to 64 bit. Otherwise this system has served me well for a number of years, through a number of computers, with minimal effort.