If you happened to get a cabin with a TV with the correct video input jacks available, the odds are you won't be able to change the input source on the TV with the remote they provide in the cabin. (They lock it to the cable input so they don't have to run around "fixing" broken TVs. So you would also need to bring a universal remote control and its instructions so you could program it to control the TV and allow you to switch the inputs. On top of that, with a Wii you need to bring the IR sensor bar and calibrate that to the setup... all in all I am not sure its worth it. They should be able to play in the camp carnival area or there would be something else going on to keep the kids entertained...
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise
NCL Dream October 2006, RCCL Mariner OTS June 2007