I have written https://github.com/efrecon/sshd-cloudflared to solve the same problem. It provides you with an SSH connection inside a transient cloudflare tunnel. The connection is only accessible to the SSH public keys stored in your GitHub account.
This is the only reasonable way to ever do this, requires no effort, just copy paste one of the examples and you're done. My only gripe is that the most secure option isn't the first example in the repo. Limit access to the actor and put it behind the debug only flag and you're good to go. Still, I remove it after the fact once I don't need it anymore since it feels a bit too sketch with secrets available.