Just haul your PC out to the room for the day. It's not something you'll be doing too often. Get accustomed to the REW program in the location the PC is at now, and even hook up the microphone and use your crummy PC speakers or whatever to get familiar with the way REW works.
then on the day in question, haul it out and do your thing....
See
here for all the info on hooking up REW...
brucek