Failover of a control plane node in single node/ HA Kubernetes Cluster created using kubeadm

Hi ,

I have the following doubts:

Scenario 1: kubeadm cluster version upgrade (single control plane node cluster), when the control plane is down during upgrade.

If one of the node/pod fails, and then the master node fails (due to upgrade/ irrespective of upgrade), would the cluster have to be manually restarted and how will etcd get the state of the pods post restart?

Scenario 2 : In case of HA control plane cluster, if there are 3 control plane running, and one of them goes down (due to upgrade / irrespective of upgrade-hardware failure) .

Would the control plane node be automatically created ? If Yes, what version (new or old)?