We had that happen at a KOA we camped at for years. Their cable supplier required all sites to hook up to there box at the site from now on (connection kit supplied at check in). Well, not everyone can use it as was our case. It would require dismounting the TV to get at the rear to hook this up and run a wire through the window as you said.
Needless to say we ended up using the antennae with barely two channels to watch ( bad reception). We expressed our displeasure and suggested a discount would be nice. They told us only a few like us had problems, no discount given.
So voting with our dollars is great, we'll never go back there. If we were notified ahead of time I would have cancelled. But because of that this year we will be setting the motorized dish on the roof up with a box of our own. Never wanted to spend the money on the box and service before as we aren't using it all year. It's already setup, just needs service hooked up. Problem solved.