I just got back from a Cruise on Adventure, caught a 3 meal package for $60 each. Went to Chops on departure day, and made 2 reservations for sea-days, despite what was said, did not have to dine on the first night.
Picked the 3rd meal as a lunch at Giovanni's for the last at-sea day on day 5 the day before. Easy peasy, if they have an opening, they'll make it work, at least in my recent experience, "your mileage may vary", lol...
BTW, Giovanni's was great, I was disappointed in Chops. It was good, but not what I expect from a top tier steak joint..