Thanks for the replies, guys.
Nutlink - yeah, that solution is how we play most games when he comes home, and that's what we would do with GRAW if it calls for the CD. I was just checking if the game actually checks the CD code for LAN COOP, like it would for online play (or like the Battlefield games do for online play).
As far as the EULA - I own multiple PC's and have one income. I am essentially one user as far as the EULA is concerned. I will not be buying several copies for all my machines, that makes no sense. But thanks for the feedback, Pritzl.
One game that works great over LAN is Company of Heroes. Does not call for the CD on startup. What a great game.