I've only been on one cruise, but when I entered our cabin for the first time I could detect a stale cigarette odor. But then, I have a nose like a blood hound and always smell smoke when I walk into hotel rooms. I now take a portable air purifier with me whenever I travel by car. I didn't take it on the cruise since I didn't want the added weight. The smell in our cabin cleared up in less than a day.
Thanks, Neil, for the info about connecting cabins. We're booked in a connecting cabin and would hate to have someone smoking next door and have the smoke creep into our cabin. I'll try to get the cabin changed.