We were wanting to spend Thanksgiving at HHI and also have the 7 month booking window. We wanted a two bedroom but they only have one bedrooms and not on Thanksgiving night. We booked the day before and the day after and are on the wait list for Thanksgiving night. If we don't get it then we will have to cancel the trip. If I was you book as early as you can but also ask what the availability is for all your days. You may have to call back each day to add on your nights but they can tell you what availability looks like.
Goodluck