are you denying that larger ice rinks wouldn't free up some space? this would make better skaters a premium, and that would mean people would want faster guys on their teams than the bigger strong guys who cant really skate. this would just create all around prettier play.
obviously you cant compare the nhl to the olypmics because the olympics are the best of the best. but, if there were larger ice rinks, more emphasis would be on speed than clogging things up, and the speed aspect of the game is what makes it exciting.