Assuming the last cancel date is after 9/16 for your current reservation and any new ones you make, you could book the one available night now under your account and then keep trying for the other nights. Even if you wind up piecing this together as multiple sequential reservations, as long as all of them are for the same room type, the hotel should be able to keep you in the same room for your entire stay. Just let them know at check in. I did this recently when I needed two rooms at a property for a two night stay, Due to when rooms became available and using Chase FNC's, it was four separate reservations. Hotel had no trouble keeping us in the same rooms for the entire stay. Finally, as others already noted, don't cancel the reservation under your husbands account until you have successfully made a new one for all of the nights under your account. You have a few more days left in the booking window for the promo to see if availability opens up. Good luck!

--Jon