GNU tar, and as far as I remember, proprietary unix tars, have ability to pour contents to a _remote machine_
With gnu tar it implemented via "rmt" program.

The default is to use "rsh" for transferring data, but there is a tar option that assigns the "rsh-command", so I presume you could redirect it through ssh, too.

Remember though that ssh encryption/decryption takes its toll, and with sizable backups you will be set back very considerably, both in transmission times and in CPU load at least.

P.S. .. and for processing without human intervention one could use "ssh-agent". After initial sending of keys everything should automate routinely