Would it be possible to make an extra "overflow" server for each data center? I know the ability to get new servers right now is hard. I mean maybe in the future, for big expansion pack launches especially.

Take Aether Data Center for example. It has 8 servers. What I have in mind is adding a 9th server that no one can make their home server. It is exclusively available when it is turned on by SE. Treated just the same as visiting a server, you can go quest, level, party finder, etc. It just isn't your home and your character will have to report back to home server(could have a live queue countdown to slowly allow, or go back home next log in.)Then lets say after 1~3 months, server load begins to trend lower and normalize and you don't need the overflow server anymore. Disable it and turn the power off. Assuming you own them and can do so.

How feasible is this?