Closer to the con itself, many people post up that they're looking to share the room in the hopes of bringing the individual cost down quite a bit. I know that with Hotwire you can cancel at any time without penalty, so it might be worth trying to find a roomie. That way you're out less money, and you don't have to worry about the travel. Also I don't believe that the overflow hotel is sold out yet, and that's right down the street, about a 10 minute walk, or you can check with the Hilton next door.