It was available as late as 2 weeks ago before I left for AZ.
That is only the Friday night, the Saturday was priced at $329, I think.
When I returned, it was gone. However, as I have noted, if you check daily, or weekly or whatever strikes your fancy, the rate may re-appear. However, I think it unlikely -- at least this far out -- for the Saturday night rate to drop or the package to appear for that night as it seems to be the one night where all bets are off.
That's why the EEO cert is so valuable -- you only need to have the room be aviailable at a public rate for you to use it as the second night.
Good luck!
PS -- the deal you got is not bad at all! If all things were equal and I could not get the Marriott, I would go for the Hyatt Regency just across the way, as it likely will be FFN promotion time again!