Creating a "maintenance" page for my self-hosted sites

I selfhost several public-facing sites, including my personal blog. I'll be needing to relocate my servers soon, though, and I wanted something more "proper" to display in their place while the servers are offline.

I won't repeat the whole post here (see link), but I ultimately set up a CF worker that I can enable with the flip of a switch whenever my server will be down.

It's a temporary, hosted solution to a common self-hosting problem, so I think it still fits here... but no hard feelings if mods decide otherwise.