I can tell you what I did. I subscribed to the "Swiss Backup" at Infomaniak (27€/year for 200 GB), installed rclone at opalstack, got the parameters from Infomaniak and set up a cron job to send backups to Infomaniak every night. I also wrote a script that checks the latest backups at Infomaniak every morning and emails me a short report. Feels quite safe :-)