If you dont plan on going far while in Canaveral, book the show that day since the ship will be docked and there wont be any rough seas for the early performance. Yes rain might still happen but at least you've eliminated 1 of the risks.
But also, you say that this October they canceled or cut every performance, so you were on the 10/1 sailing I believe that was in the wake of a hurricane? The 10/8 sailing did not cut a single performance short or cancel even though the last night was pouring and very few people were in the seats. (I watched from the side near the rock wall). When you sail in hurricane season, you never know what will happen even week to week.