Nope. The only examples I can think of where multiplayer is possible with only one copy is Nintendo DS/3DS games (I think its called Download and Play), and early Blizzard games (the other player needs to install a "spawn" copy).
As far as I know other companies haven't done anything like that. There's an idea for ya, Beamdog. You'll get free advertising as more people are exposed to the Enhanced Editions, and if players with spawned copies want to play solo, they'll have to buy the game from you. You'd probably turn this idea into a dog's breakfast, but I think its worth the attempt.
Post edited February 08, 2017 by jsidhu762