I back up to an external disk, then run a script that zips the files for that backup into an archive. That backup folder is watched by Google Drive, so its contents get mirrored to the cloud. If I lose the external drive I've still got backups.I'll pick up a clean zip drive to save to as well.
I periodically cull old backups from the external drive's backup folder and keep ones that are significant, like the one just prior to a firmware change, and the one immediately after. I'm careful to lock and color code the ones just prior and afterward to make it easy to know which I want to keep.