I was going to be out for sure this year because of the Embassy Suites non-refundable deposit but a pair good pinball friends suggested the Hilton Garden Inn across the street. I live in Atlanta so it's not a sure-thing to decide if I can go a year in advance. So I now have a reservation there. Edit: I've been at TPF dragging 4-6 friends every year since the Hilton Anitole year.
Also, as a Hilton Diamond member I stay in a lot of hotels. I run into hotels all the time that have a 72 hour policy. I would think the Embassy (a Hilton property) could change their cancellation policy for the rooms in the TPF block to a different time period. I assume they could make it anything they want unless there are other Hilton policies preventing it in this case. The point being there very likely are options between 6pm day of arrival and non-refundable a year in advance.