I believe that both NCL and Carnival are in the process of changing the rules so that there is no smoking in cabins. I would check their websites before you decide whether to go or not. I don't mind the change, even though I am a smoker, I hate the huge volumes of second hand smoke you sometimes encounter. I go up on deck, usually all the way aft if I want a smoke. I don't smoke in my own house, or anyone else's, so I'm not going to stink up our cabin either.
See, some of us do know how stinky we are!