Well hello there!
From my experience there's quite a lot of people using laptops to play SH4.
Please look at these threads:
http://www.subsim.com/radioroom/showthread.php?t=139474
http://www.subsim.com/radioroom/showthread.php?t=139256
Edit: Also I think you don't need the DVD to play the game since patch 1.3 so you don't even have to have it with you.