Comment by bob1029

I feel like this is really only an issue with true site to site VPNs. Client to site shouldn't have this issue because the VPN concentrator is like a virtual NAT.

The best strategy might be to maintain the ability to easily reassign the network for a site. If every site is non-overlapping the problem does become trivial. I'd much rather fight a one time "reboot your machines tonight" battle than the ongoing misery of mapping things that do not want to be.