I'm doing that right now. I have Pop booked for next Dec. Obviously the BRP isn't even close to being out yet. When I asked my DU agent how it would be handled, she told me that I make my reservation as usual now, with the one night's deposit. Then, when the new BRP comes out, she will make me a new reservation, using that rate. I will have to send along a new deposit, but the old one will be credited to my cc. It seems they can't just transfer the old reservation over to the new one using the BRP. I was hoping to not have to send in two different deposits but looks like I'll have to.