Nothing wrong with using what you've got and upgrading. And the beautiful thing about Docker is you can just spin up the container elsewhere, point the mount points to their new locations, make sure your perms are good, and continue like nothing changed.

It really is so much easier now. And with UnRAID acting as my container host, it saves everything I spin up (permanent or not) in its last state as a template, so if I need to destroy my docker image disk (which I recently ran into) all I need to do is find the template I was using from the dropdown they give you and click Create. Not a backup solution (which you should also have), but it's such a time saver if and when something goes horribly wrong, or if you want to spin a container you used to use but since destroyed back up.