Ques - drain cordon, uncordon

I understand that a single pod created and running on a node will need the additional parameter to drain the node

kubectl drain node01 --force

would this be an opportunity to create a replicaset with a replicaset=1, thereby allowing the kublet to reschedule the pod to another node automatically during the drain operation?

You could; in realistic situations, people don’t run stand-alone pods to handle real tasks; they use deployments or other resources to handle the pods. A replicaset is one of these resource types.