I suppose temporary vSZ is successfully migrated already, but I want to share my experience - may be it will help somebody in similar situation (which is very common).
When working vSZ must be moved to new DC and change external IP addresses as well, we install 2 completely new nodes (with external NAT IPs as needed for customer site, even so they are not available on our site), join them to existing
cluster, and than remove old nodes from cluster. Than we just shutdown both new nodes, make backup from them to mobile HDD using HPE VM Explorer software (or any other similar tool). VM explorer is convenient, as it downloads and compresses VMs in one step, but you can also use just VmWare client Storage browser + 7Zip, it just will take much longer time to copy files without compression.
Typically, 100GB vSZ virtual machine backup takes about 10-15 Gb. Than we move this disk to target DC and restore virtual machines on customer VmWare hosts.
When nodes are restored and started, we license new nodes
(if previously RTU licenses have been already registered to temporary
nodes, we make RMA through LIMAN, to move RTU licenses to new nodes).
When new nodes have been added to cluster, controller IP list on all APs has been updated, so when new nodes are connected to Internet and licensed, APs connect to cluster automatically.
We have done it multiple times, main benefit is a fact, that WLAN, user, security and AP information survive this migration. It is especially good in cases when APs are distributed, for example - in different countries.
Hope it helps,