We ended up booking a last minute Christmas cruise (beginning of November) to join friends. They are on anytime dining, while we were only able to get late dining. We would really like to be able to eat together - at least a couple of times. How easy is it to switch once on board? This is our first time cruising over Christmas - so we know it is much busier, just wondering if there is any likelihood that we will be able to switch once on board. Has anyone else had success switching on a full cruise?