have you tried using a vpn, e.g. tailscale?

extremely easy to set up, if you are a selfhost purist, there’s headscale as a direct alternative.

only really good at doing stuff in a personal workspace, not really made for exposing to the public internet, still very possible tho

kde or gnome or what DE/WM you using?

if yiu want them timed, you can just put the respective settings command in your crontab

https://hannes.hauswedell.net/post/2023/12/10/darkmode/ mught help with the commands