I agree that Redbox is a great option.
Another option would be local Libraries. Depending on how long you plan to stay in any one area, you may be able to get a temporary card, to let you borrow movies, books, etc.
I have an "AirCard" with Sprint, which I can use for my computer when on the road. I like the idea that it's MINE, and I'm not sharing with who knows how many other campers with a Wi-Fi connection....so I can get movies or TV shows on the computer. Cost is about $50/month...I've had mine for years, so it still has "unlimited" data plan. Not sure about now days?
Have a great trip!