Set up load balance for ES cluster

I have a ES cluster with all nodes in same sub-network, so if this network goes down, my load balance will redirect traffic to a different IP, so this IP should be a extra node in the cluster
HOWEVER in regular use I dont want to use this extra node because it is geographically very distant and a lower resource machine.

In other words I want to keep this node inactive and activate it only in main nodes in cluster goes down ?

Is this something possible ?