Hello, friendly Cloudflare employee here... there's a much simpler alternative to managing cache policy if your whole website is static. We built a tool for deploying static websites to Cloudflare [1]. It watches your Git repo for changes, then rebuilds your site and serves _all_ the assets from our edge servers. No need to configure page rules or cache policy, because there's no more origin. The free tier covers 500 builds per month (at most, you'll do 1 build per commit, so you should be covered just fine).
I helped develop Tunnel over the last ~3 years, and I love it, but it's definitely overkill if you just want to serve some static files on the edge.
(Please delete if this goes against HN policy, I'm trying not to be a shill here, just help tristor avoid spending an hour configuring page rules and cache policies)