If you absolutely must have reliable WIFI, you cannot depend on any campground. For all the reasons stated above, some places may work, others may not. If you "absolutely" need it, you can only depend upon your own, like your mobile phone hotspot. But that is still restricted based upon your mobile phone coverage.
About television reception? If you are using your RV antenna (over the air), you are subject to only what is available at whatever geographical location you may be at. Even withing the same campground, one campsite might receive 40 over-the-air stations and the one right down the road from it may receive only 2. Any number of "geographical" factors can cause a signal to reach your antenna.
Cable television at campgrounds? Well, there again, every campground is different. If you are depending on campground cable, well, face it, you won't be able to depend on it. Maybe if you are staying at a long-term campsite, RV Park, or an RV Resort, they may have working functioning cable television. But if you are transient traveling, you never know what your going to get when you land into a never before visited campground.
The best assurance is to have your own satellite television system. But there again, once you are out of your local (home) area, you most likely will not get your local stations. You'll need to contact your provider and have the "local" stations switch to your current location. But the main satellite stations will continue to work.
But there again, unless you do good planning and selecting your campsite, if you end up under trees or parked by some kind of tall object, you satellite dish will be blocked and you end up with no signals at all.
Basically, if you really need and really need to "depend" upon WIFI or television viewing, you really need to provide your own resources. The only assurance is your own resources, not someone else's.
