Thanks everybody for all the good help and advice. I called DirecTV today and ordered the D12 receiver as some of you advised. DirecTV sold me one for $20 since I had the maintenance plan. :)
We added the receiver to my current account as a "seasonal" receiver. When I head out in the RV, I call them and they activate the receiver for $6 a month and deactivate the Genie at home. I get my normal TV package then, without equipment costs at the sticks and bricks. This normally incurs a one year contract, but since it's within my current 2 year contract it doesn't apply.
This seems to be the best and easiest solution for me. Thanks again everybody for all the great advice and help you have given me!!