I don't have offsite backups yet (but read on). Currently, I auto-backup daily at 4am, my entire fedora desktop using rsyncbtrfs https://github.com/oxplot/rsyncbtrfs which does an incremental backup on btrfs using subvolumes. I have everyday backup for last 4 years and I can access any version of any file at any time with no preparation (ie just cd into the appropriate directory for that day).

I have also written https://github.com/oxplot/cloudnbd for offsite backup. It presents any cloud storage (via pluggable backends) as linux block device which you can format to FS of your choosing. You can then mount it, RAID it, etc. and do crazy stuff with it. I don't use it yet because it's not well polished (and I'm lazy) but that's my ultimate weapon. It encrypts everything on the client side too so that should make NSA's job a tad harder.