Our first cruise we were worried, mainly because we didn't believe that there was no need to claim our luggage that moring in Orlando. On our second, it arrived before we even got to the room. I wouldn't worry about packing dinner clothes in a carry on.
Besides, dinner the first night is pretty casual. They understand that some folks (very few but some) might not be connected with their luggage yet.
We had late seating and I had the luggage completely unpacked and some ironing done by the time we left to go to the early show. And that included going to a DisMeet and the sail away party. I think the luggage was in our rooms between 1:30 and 2:30.
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