Thanks for the advice, LisaS.
I did book at SSR and will call at the 7 month point to try to switch... is that 7 months from the first day of reservation or last?
Depends on how many points you have or how much risk you are willing to take.
If you have enough points to keep the SSR reservation until the AKV reservation secured, my advice is to call for each day and if it's not available, get on the waitlist for that day. That gives you the best chance of getting the AKV reservation. You don't cancel the SSR reservation until the AKV reservation is complete, so there is no risk. If you don't get all your days at AKV and don't want to move, you cancel the AKV reservation and stay at your home resort.(There are some other considerations with holding the SSR reservation, depending on your banking deadline and your other plans for the points).
If you don't have enough points to hold the SSR reservation, then you have to decide if you are willing to risk moving back and forth between SSR and AKV during your vacation.
*If not, you make one call 7 months from check out (of the last night). If you don't get the reservation, you go on the waitlist (for all the nights to become available at once) and cross your fingers for pixie dust. This option eliminates the risk of moving but is also less likely to come through than calling day by day.
* If you are willing to take the risk, you call 7 months from the check out date of the first night and reserve that night. You tell the CM that you are making a day by day reservation and that your final check out will be (whatever it will be). The CM will note that on the reservation and hold the confirmation until you reservation is complete). If any of the nights are unavailable, you waitlist for them individually and hope for that pixie dust. Waitlisting for an individual day increase the chances of your entire waitlist strategy working, but it is possible that you could end up moving back and forth between AKV and SSR. Only you know if your family would be OK with that.
Note on day by day: If you have to cancel a day of SSR to book AKV, you also run the risk of getting an inexperienced CM and losing the day at both resorts. You can eliminate that risk if you have at least some uncommitted points - enough to book one night at AKV. Then you can book the AKV first, and cancel the SSR day afterwards. The cancellation will give you enough points to make the next day's AKV reservation.
I know this all sounds complicated. But after you do it, you'll see that it's really not and if you get what you want, I'm sure you will think it was worth it.
Good luck!