We have been very successful booking HH at 7 mths. June, July and most of Aug can be tough to get. It also depends on type of room. Studio's go first, 1 br are a little easier to get and GV are usually gone. If you're a little flexiable on the dates, you should be able to get your reservation.
I have at 8 months out, called with 2 different dates and check if their where rooms available at that time. Then called each day at the 7 mth mark to make my reservation based on their reply to increase my chances.
This year I called at 6 mths to upgrade from a studio to a 1 br. We went on the wait list. Two weeks later we got our 1 br for June 15 week. A little bit of pixie dust worked!
Good Luck,
Sandy