We get great HIGH DEF TV just about anywhere we go using the WINEGARD BATWING antenna with a WALMART SPECIAL VIZIO 22-inch Digital HDTV setup in our off-road POPUP camper.
No way would I invest in a high $$ system to use just for a month haha...
My BATWING Antenna is mounted on easy up pole on the side of my POPUP camper and is easy to setup.
If your WINEGARD BATWING antenna on your Class C looks like this this you are good to go... (NOTE the addition of the small dipoles)

The NATIONAL BROADCAST is available for free to general public and all you do is point the BATWING to the local town that is broadcasting the HDTV signal. Run a scan from the HDTV menu to log in the available stations and watch HDTV... Nothing else needed if you have a digital HDTV LCD TV set.
My OFF-ROAD camper looks like this with the easy up pole and BATWING antenna for our OFF-ROAD outings...

This works great for us and is all free to use here in the US.
I'm sure the high $$ system guys on here will describe how you can use a Satellite Dish setup to subscribe to SAT TV for your Class C.
Roy Ken