Sure, you can use `git bundle` to export your repository to a file, then upload it to the archive. There's a nice command-line tool for doing the upload (https://github.com/jjjake/internetarchive), so you can easily script this so that it's automatic.
I don't expect any service to stand the test of time.
So I want to spread my code across multiple services. And when one goes down in 10 years or so, clone it from one of the others to yet another one.
Paying is not an option. Because I want a hassle free solution. Paid services would be prone to even more issues. For example when I change my credit card I would have to think about updating the CC information. At some point Credit Cards might go out of fashion. And the provider and I might not have a common payment channel anymore. Or the provier raises their fees to a level that I find too expensive.
I want a solution that I can set up and then forget about it for as long as possible.