Why don't you call the hotel directly (not GP)? In my experience, there are only a limited amount of award nights that GP can offer. I'm not even sure if the hotel can (or does) increase this number if more rooms are available. However, if you call the hotel directly, they can offer you an award night even if GP can't. They would much rather take the ~$100 of so that your award would bring them from GP than leave a room empty. And the later you call (e.g., Sat. morning), the more likely it will be that they will offer you an award room because they will better know if they will be fully booked or not.