EVERYTHING is available at the 11 month window. It's the 10 mo, 29 day window that you need to worry about.
Seriously, though, if you are confident in your travel plans when the 11 month window arrives, there's really no reason to wait to book. Particularly for the GVs at OKW which are so limited in number. As long as you own OKW, go ahead and book the room as early as possible to guarantee your dates.