I’m looking for a diskspace of possibly 1TB online
Edit: my idea is to use it like as an external harddisk for everyday stuff. Encrypt the disk, put my filesystem on it, mount it as external drive kinda. Never worry about backups or lost data etc, as the provider would take care of it
That’s unlikely to perform well enough to be usable at all. You’d at the very least need some sync method which just updates the blocks you wrote to, and that rules out a lot of cheap storage.
You’d be better off with either cloud storage a la Google Drive or Dropbox, either mounted from the remote location or used as storage for a sync-based backup solution. You could have it upload things instantly if it listens for save events in inotify.