Carnival does for sure. Our friends are putting their three kids in the room with them. I totally understand. I'm all about saving money too. We are going in March and we'll have two teenage boys sleeping above us. We've done this a couple of other times. We just make arrangements ahead of time for showering and getting dressed.
We have found that the extra space, and extra bathroom and TV sometimes can be had by getting two connecting rooms. We did this once on Royal Carribean and we are doing it on the Blogger's cruise. the cost difference is minmal, and is far superior to a suite in my opinion fro a family of four or five, because we get about the same amount of square footage as the suite, an extra bedroom, TV and bathroom for a lot less money. For only a couple hundred dollars it sure beats trying to cram 5 people into a 150 sq. ft room with 1 bathroom.