I have a work-around that *might* work for you, but has not been thoroughly tested.
There is a firm requirement however that there must not be any conflicts with the guest ID, or the node name.
On node1 (with guests)
Create a new cluster or get join information.
On node2 (with guests)
scp -r /etc/pve/nodes/* to node1:/etc/pve/nodes
rm -r /etc/pve/nodes/*
Join cluster.
Please realize there is potential for things to go sideways!
I've done this to re-assemble a cluster I've recently had to pick apart, and can't provide any details on long-term issues or risk.
I cannot suggest this work-around at the moment for nodes that have never been in a cluster with each other.
I've done this with online VMs! and they remain operational through the process. The join cluster process will overwrite the contents of /etc/pve/nodes with copies from the cluster... so copying your new node directory to the cluster with scp will indirectly restore it on cluster join.
Good luck.