[eridius]

Encrypt your backup using a secure password that's stored in the backup (in your password manager), and then just have a physical copy of the password stored in a fire safe, or safety deposit box, or something else of that ilk. As long as you haven't suffered catastrophic computer loss, you can recover your password using the password manager. If your house burns down with all your stuff in it, you can use the physical copy to access your backup (or, ya know, some other mobile computing device like a laptop or smartphone that also has access to the password manager).