I'm trying to use Cloudflare's fail-over system, but I won't be able to transfer the domain's DNS to Cloudflare. The owner of the domain has offered to set up a CNAME but I don't know how that would help, because the site will be hosted under the root domain, not a subdomain.
I'm going to host the site on an AWS server, and I plan to keep a copy of it on a backup VPS at another provider like Vultr, and I would like Cloudflare to be able to do a DNS failover per their offering. Can this be done if I can't bring the DNS into a Cloudflare account? Are there other good ways to set up a failover mechanism without having direct access to the DNS?