I doubt you can afford an actual satellite, but I would second the recommendation for the Winegard Pathway X2 antenna and a Dish For My RV (Outdoor) account. If you're not a full-timer, you can deactivate and reactivate the account when you're not using the RV. We have the Pathway X2, a Wally receiver and an outdoor account and the setup works very well for us. You can even put a hard drive on the Wally and use it as a single-tuner DVR.
Rob