We booked a Jan 13th family cruise with 2 adjoining but not connecting rooms. Because we wanted to use two discount codes (one for each room) when we booked, my wife and I were separated. Obviously we plan to sleep in the same room and have our three adult sons in the other room. Can we do this switch before we board without messing up the discounts or do we have do do it once on board? If on board is the answer, how do we do this swap as painlessly as possible?