[sidarape]

You could use a static website generator such as Jekyll or Hugo. Then, if the tools stop working for any reason, you always have the generated HTML than you can update.

[kaushalmodi]

Hugo has a single static binary. So the site will always generate the same way with the same binary.

[2038AD]

... with the same execution environment

[syntheticnature]

They already are, hand-rolled: "There are a few scripts that generate pages"

[iamaelephant]

Or you could not do that. Did he not just show that his way works just fine?