I can also confirm using codes for already booked room and usually your deposit will transfer right over to your new rev(one exception is if you book online you will have to cancel and rebook and you will have to pay the deposit again while you wait for a refund of your old deposit, usually the refund comes after the deposit comes out). If you want to do this MAKE SURE you get a room only reservation, not a package deal. The package deals have much stricter rules on canceling revelations.
a good strategy is to book the maximum you can afford at rack rate, set that as your savings goal and then change your plans as discounts come along. Doing this allowed me to save for a week at POFQ and then switch to the AKL (for 20$ a night cheaper) when the AZZ code come out