I called back this morning and got a GREAT CM. She said she'd try it and see what happens. She was able to get the offer for the entire stay 8/14-8/21.
The deposit does need to be made immediately with the rewards card, though. So she just switched my ressie from september to the new dates with all the package components and told me to call back in a few days when I have my card and they'll apply the code. So, I have my deposit from the September ressie to hold it for now and I'll make a second deposit with my new card and they'll switch the ressie and apply the payments from my other ressie to the new ressie balance as well. She put me on hold for several minutes to check with a manager to make sure that would work.
But she COULD get me a ressie for the offer for the entire stay checking in on the last day, just couldn't hold it w/o the card. I got the quote though, and the price difference was just under $1200. That's for 7 of us w/2 value rooms, PH, and QSDP, 2 adultis and one kid adult (11yo) and 4 more kids.