I can't help you at all since I will be sailing on the Dream on Sept. 14.
Are you sailing on her.
I am hoping to find some information about her as well, as long as some Cruisemates who maybe doing this cruise also.
I have posted on the Norwegian MOB thread, but have had no responses yet.
I was in a BA on the Dream many years ago but only two of us. You should be fine. The cabin is 157 sf just a bit smaller then the newest ships. With two twins that can be made up as a queen and the sleeper sofa you should fit easily. There is I believe a curtain that separates the two sleeping areas.