THe onsite perk is that you can call at 180 days from check in and book up to 10 days worth of ADRs so you can call 5/6/08 and make all your ADRs.
But if you have no luck getting a CRT ADR at that point, then you should try again at 180 days from Nov 5th which is 5/9/08 because they do hold back some CRT tables/ADRs for those staying offsite.
Hope this clears things up.