I said this before many times and I'll say it again, consider self-hosting your projects on a solution like GitLab or Gitea to avoid this sort of situation. [0] GNOME, Xfce, Redox, Wireguard, KDE and Haiku all have self-hosted on either cgit, Gitlab, Phabricator or Gitea. [0] https://news.ycombinator.com/item?id=23676072
The downside is that a lot of these self hosted archives will have disappeared 10 years from now. Meanwhile, I expect many forgotten repos to remain online with Github one way or another for a very long time. If you do go the self-hosting route, add a mainstream host as an additional remote and push your commits to both.
In fact, with all these free services, I'd probably say it's well worth automatically making remotes (at least) for GitLab, GitHub and having a local Gitea for everything you do. This should be resilient against specific outages, or GitHub simply deciding they don't like your project name, or some other disaster.