I do this today with Nomad/Consul. Hashicorp's Raft+Serf implementation allows for shocking amounts of latency between servers/clients. I have several centralized server clusters (the "servers" _should_ be geographically close, the "agents" can be far and wide), and agents more than 200ms+ away, and across multiple clouds/on-prem. Everything works just fine.

I've legitimately considered running some kind of simple SaaS and behind the scenes running a Nomad cluster and having the remote SaaS agent just be a Nomad client.