I'm fortunate to only depend on a single platform, Linux in my case, so I rent a 1TB vps[0] to whom I rsync[1] every day . Then depending on the criticality of the service I'm backing up I create weekly/daily/monthly snapshots (rdiff-backup). I encrypt sensitive data using symmetric aes 256 (gpg).

[0] https://www.time4vps.eu/

[1] http://javier.io/blog/en/2014/04/08/backups-git-rsync-rdiff-...