I understand and we are going through the same thing. FI handed out STD's to everyone at his station and found out he was transferring the next day. We talked about it and decided to only invite those he is closer to. But of
course now that we did the transfer was delayed and may not happen!
I would stay keep those form the old station, no you would not want to un-invite anyone, and you are close with them so you would want them with you on your day. If invitations are out then I would think the guys at the new station
would understand. If anyone said anything (not that I think they would) just be honest with them and say I'm sorry the invitations are out and our guest limit is over.
I have seen a few guys get married over the years and some invite all, some none, and some invite just a few. It's been my experience they understand. And honestly they are men so this will go over much easier than we were
talking about women!