We did it years ago, postponed the trip a full year ahead. It was within our 45 day window so if we'd asked for a cancellation we would have been out $400.00 (2 room deposits) so we just rescheduled. They just moved our deposits and all our payments to the next reservation. If you were going to cancel and reschedule and were outside your 45 day window, it wouldn't be an issue. But since you said your paid off trip is next month, I'm guessing you're inside that window....where if you cancelled you'd lose your deposit?
In that event, I don't think they can give you back any of your money without you losing that initial room deposit of $200.00 per room. That would require cancelling and rebooking, if you're willing to lose that $200.00 per room deposit you can do that and you'll get a refund on the balance though.