THIS IS A POST IN PRAISE OF SNAPSHOTS.
My PeerTube upgrade was a horror show: lost server connection during the upgrade and then PeerTube was automatically removed from my YunoHost server... the routine backup by YunoHost of PeerTube didn't restore... in short: bad, very bad outcome.
I hyperventilated for a few minutes and then... hit "Restore" on the VPS snapshot I had captured before the maintenance operation and... everything went back to normal.
Heart still beating a little fast but I am in AWE of the powers of SNAPSHOTS, ouf.