Both BCV and VGF have a risk of filling one or more of the nights you want before 7 months out, with BCV having the higher risk. Moreover, you should not assume for that time of year that it is even certain to be able to get SSR at 7 months out for all nights of your trip (likely but not 100% certain). What you should do, if you desire that split stay, is to make two separate reservations now at SSR, one for for Nov 12-16 and one for Nov 16-20, and do not try to have MS merge or link them. Come seven months out. you can then modify the Nov 12-16 reservation to VGF or BCV if one is still open (or even potentially Riviera if open for that time). If at 7 months out, you are unable to make a change, you could still waitlist for a desired change for that first reservation time. Once it becomes apparent that waitlist will not work, you can have MS merge the two SSR reservations so they become one.