I myself am unable to book well in advance so I am sympathetic to JGill and envious of MileKing.

JGill - you may want to see if there are any alternate properties (Courtyard, Residence Inn, Fairfield Inn etc.) which are available. I myself faced a similar situation when I wanted to book with Marriott (about 2 months in advance). I could not get the property I wanted because of capacity controls , but was able to get an alternate one.