Copying snapshot to cold storage

What’s the best approach to copy a single snapshot to some cold storage? Given that the server I’m backing up daily is remote and the restic repository is also remote (sftp/cloud).

All I’ve come up with so far is to setup a 2nd repository, copy a single snapshot from the first repo into that, then rsync that to a disk which I then disconnect and store offline.

I don’t want to just copy the entire main repo to cold storage because that simply takes too long for the amount of data in there.