We also have been at some campgrounds that had great wifi and cable. Some charge extra, but the ones we found it was included in the rate. We use only our antenna for television unless the campground has included cable. Many areas we have had as many as 20 channels. We even had a large selection of over the air channels out in the forest 24 miles from a small town in AL where we hosted. Depends on location, trees and signal strength. Where we host in the summer, we only get FOX network after the leaves pop out on the trees, so just depends. We do have our own mobile jetpack thru verizon that we use when campgrounds do not have wifi, or it's a useless wifi .
I also agree that many times it's someone in the park streaming movies, video or tv programs that uses the available bandwidth and ruins the wifi for the other campers not even allowing them to get to their e-mail. It's very selfish as far as I am concerned. We do not stream - ever- except without own mifi.