Provide the ability to add a 'Standby' node in a different region from the active node.

I'm aware a cluster can have a Read-only node in another region. I'm also aware it's possible to have up to 2 standby nodes in the same region, but it would provide better HA for a standby node to be hosted in a separate region from the active node. This would of course cover a regional outage event like a complete outage for NY3 region.