I archived my old laptop with
sudo dd if=/dev/sda status=progress | ssh firstname.lastname@example.org "dd of=/data/mbpssd.img". I did that from an Ubuntu 20.04 live USB. The command runs dd as root to read /dev/sda, then pipes that to ssh, which reads from stdin and outputs to disk.
Once I did that, I used
losetup -fP mbpssd.img to mount it, then
mounted the partitions to make sure it worked. There could be some corruption that I didn't notice, but SSH is TCP and the encryption would fail if there was a corruption right?