This is just a hypothetical question to satisfy my own curiosity.
Our company is based out of Site A, this is getting a bit full and we are having to setup pilot offices for teams, branching the teams onto many smaller sites. An ideal solution would be to move the entire company to a new office that is big enough to house all our staff with room for expansion (Site C).
We have our own server farm at Site A which we then have replicated at Site B (which is fine where it is).
How does someone move Site A to say Site C? We have no real room to have down time - there are a lot of customers on our servers.