We've been through this question as well. After buying a Rankarena 20 inch 12 volt/240 volt flat screen T.V. and powered antenae for our Cub camper, discovered the volume of T.V. annoyed nearby campers. (canvas walls are pretty thin and don't stop much)
I also found the messy job of laying cables, pluggin in stuff everywhere, mounting the antenae then trying to tune in the free to air channels only to discover recption was lousey or non existant, or only one channel available (channel 2) simply was not worth the trouble of lugging all that gear around.
Besides, don't we leave home to get away from all that stuff ?
If you want to find out the weathet tune the car radio to ABC. And if it rains, you can play solitaire with a real old fashioned deck of cards, better yet, get out your new fangled reader and read a book.