I don't think it's possible. CDN by its very nature is to send content in low latency manner to users in different geographical locations by having multiple servers also spread in different geographical locations. Users from different parts of the world might get identical CloudFlare URLs resolved to different IP addresses based on where they live, to make sure they get their content from the nearest CloudFlare's CDN server.
CloudFlare uses Anycast. However, we shift sites around between IPs frequently in order to, for example, isolate a site under DDoS from the rest of our network.
While it may be possible to create a IP-based CDN, my guess is the tradeoffs in terms of not being able to thoroughly defend yourself against attacks would not be worth the few milliseconds saved on the initial DNS lookup.
