Ok just found this, but this is to the extreme. a trade show with 570 different networks in a small area would be expected to cause problems.
Radio interference at trade shows[edit]
At two major trade shows in 2010— Google's first public demo of Google TV and the iPhone 4 demonstrations at the 2010 Apple Worldwide Developers Conference— keynote presentations using available Wi-Fi connectivity were disrupted by network unreliability. The problem was traced to massive radio interference, caused by the popularity of MiFi and similar devices for "liveblogging" from the trade show floor. In the case of the Apple conference, Apple CEO Steve Jobs stated that 570 different Wi-Fi networks ("several hundred" being MiFis[37]) were operating simultaneously in the exhibit
But a 600 room hotel is no different then any RV park, just the rooms are the RV's and there is no grass. The average MiFi has a 30 foot range so one would figure it to cause more problems for a hotel then an RV park. I have never had a hotel say I can't use my Jetpack nor have I ever had a problem using it or any hotel or RV park WiFi. In most cases it's just the park using a single router in the clubhouse and calling it free wifi. Also unless the campground is really in a remote area they probably had broadband long before most city folks. Why? Because we were installing DSL and Fiber to the Prem in rural areas because the government mandated us to before we were allowed to install it in the cities. I was installing fiber to farms so the cows had internet long before I got it in the city. I placed DSL cabinets in areas where there were only 70 subscribers available, there were more cows then people.