Can I rent a movie on a laptop the night before and watch it the next day on an airplane

About renting movies from the iTunes Store - http://support.apple.com/HT201611

Yes. You have 30 days to start watching a rental, and 24 hours (in some countries its 48) to finish once you've started watching.

You may need an internet connection to validate the rental before you start watching however. Once that is done, you can watch without an internet connection.

Generally what I do, is start the movie before leaving the house for the airport, and then I can continue to watch it offline on the plane a few hours later.