All you need for a free Cloud Flare account is a domain and an email address.
Little countries and even some little islands all have their own top-level domain these days. Many registrars around the world are pleased to sell these cc TLD and g TLD registrations.
If those IPs change, then block Cloud Flare's entire IP space, and continue to monitor the situation.
If Cloud Flare's traffic still gets through, you ask the ISP to pull the plug on Cloud Flare's racks.
It's a cash cow for everyone, but especially for bad guys.