Failover server

Hi!

I've been researching something for quite some time now, ,but i can't find a good answer. I want to setup a failover cluster, but on different locations, because of wonky internet connections. My parents are divorced, so i got my locations, but there seems to be no software witch can setup a cluster on different networks. I've read you can setup a proxmox cluster via VPN, but that you need a sub 2ms latency witch i don't have. Wich software would you use, or how do i fix this? it would be a new server so OS doesn't realy matter.

thx in advance!