This multi-server front project, Jellyswarrm is really interesting, which allows the Jellyfin clients to access more than one Jellyfin server simultaneously. I think it may do what you want when combined with server sync.
Would definitely test extensively before putting in production, hehe.
Ah, the answer to that.... I configured the server beforehand and installed it at their house as a gift, so I have persistent SSH access over VPN and can administer it remotely at will within tmux. Has worked for several years.