C
caravel
Putting in a permanent wired connection is ideal as per leeky's suggestion, though it's not needed. You should be able to get away with taking your PC to the same room as the router and connecting it up with a 2 metre drop cable (a length of Cat 5E stranded with connectors at each end).
Once connected you can install Linux, connect to the repos, update, fetch the firmware get the wireless working and then take the PC back to the room it belongs in.
Once connected you can install Linux, connect to the repos, update, fetch the firmware get the wireless working and then take the PC back to the room it belongs in.