I loved seeing the Beauty and the Beast prem-EAR on the Fantasy, and I also enjoyed Rogue One in the WD theatre there, too. But when I saw Rogue One in the theatre on land - that was amazing. I'm not saying anything against the ship theatres, but unless you live in a small town, you probably have some state of the art theatres in your area where the leg room, cushions and arm rests are designed for 2 hour movies with munchies. You could see it on land, as you've suggested and then follow up with watching it on the ship. Depending on how good it is, you may get several chances to see it for 'free'.