The GV in the Hospitality House booking category is usually booked before 7 months out. The GVs elsewhere at OKW are usually open at any time between the Monday after marathon weekend in Jan to end of Sep. except for some risk otherwise in middle of June and right around July 4. They tend to be difficult Oct to marathon weekend in Jan but you can still find some times that they may be open such as early Oct, third week of Nov, third week of Dec