I'm sorry, but I do exactly what you say is impossible.

  > Putting backups into the cloud is a terrible idea
  > and transferring large data collection over a
  > residential Internet connection makes little sense.

I work with video, music and large images. So my home backup is 3.6 TB. I now use CrashPlan: a cloud backup, who have no problem with the capacity. It took ~ 6 months to store everything, but now it just sends the deltas quietly behind the scenes.

I lost a 1TB drive the other day, and the restore worked well after a bit of jiggerypokery.

Previously I used an LTO2 tape system involving Bacula, a VMWare linux instance and a lot of changing tapes. Cloud backup is so much better