Do you book on the first day of your stay or the last? As the first day on the mark will mean the following days are beyond the 7/11 month mark. If that makes sense?!
You can book 7 nights then call each day to add a day or wait until you are 14 days in and book all at once. Owning at your favorite home resort and booking at 11 months for the majority of the rooms is less of an issue with less competition. If you book a split stay the clock starts over for the second reservation, they are separate. MS can add or remove nights to the beginning and the end of a reservation.