You have two kinds of systems: Those where you can wait for Cloudflare, Amazon, or Microsoft to come back up, and those where you can’t.
For critical systems, your developers and operations people must carefully examine the code and document all dependencies. Once you know what you depend on, you can decide whether to build in automatic mitigation or establish a limited-functionality mode.
To concentrate your efforts in the right place, your systems list must identify the truly critical systems and their dependencies. Does it?