We have several servers, and normaly everything works fine, except now...
we get a new aircondition installed. This takes 36 hours and for this time almost all servers got shutdown, only 2 remaining servers run for the most important tasks (i.e. accepting incoming email, delivering some important websites, login-server).

Everybody was informed that when they need appropiate data from the homedirs they should fetch it before take down. Long story short: Someone realized that he have run a certain program on one of the servers. No Problem, he can remote login into our login server and run the programm there without home directory (binaries are local and necessary information can be copied to the /tmp). That works like a charm until...
... the user needs to run a GUI programm. I find no easy way to make it running, usually

ssh -Y honk@loginserver

is enough but now the homedirectory is missing and ssh is not able to copy the cookies into ~/.Xauthority (as the file server with the home directories is down). Paranoid as all systemadmins

• all X-Server just listen locally not on tcp ports, so no remote X connection possible
• SSH config is waterproof - i.e. no way to set environment variables.

My Problem is, that the generated proxy MIT cookie from ssh get lost as the .Xauthority doesnt exist. If I could retrieve it somehow I could reenter it a .Xauthority in /tmp.

The only other option (besides changing the config) which came to my mind is, makeing a tunnel (netcat, or better ssh) from the remote host to the loginserver and copy the cookie manually (not sure if it the tcp->unix domain socket stuff works as expected).

Any good suggestions (for the future - now our servers are already up)?