I use Millenicom.com. The 20 Gig plan is $70/month. They sent me a MiFi which runs on the Verizon system (also functions as a router). The MiFi has a battery that's good for at least 6 hours as near as I can tell, otherwise I just leave it plugged in. I also have a Wilson Sleek in my truck and also in my 5th wheel to boost it. You can stick it in your pocket and head off to the beach, park, etc and run anything that is wifi enabled - computers, notebooks, printers, Ipad, Nook, Kindle, etc. I programmed my phone to always search for it and use it if available so I don't go over my phone allowance. I think I can run 5 devices off it at once.
To me this is a great, simple solution. I simply don't care what the campgrounds have. I always know that wherever I go I will have the connectivity I need. I know that some use their phone as a hotspot but I can't do that with mine. Plus I understand that if you do that, then you can't use your phone as a 'phone'. Please correct me if that is an incorrect statement.
I'm sure there are other solutions out there that work equally well. To each their own. But I don't think that any of the real solutions that you will need as you travel from place to place around the country will include campground wifi.
I want to make it clear that I am not knocking the campground owners. As I stated in an earlier post, it can't possibly work. If I was a campground owner, I would provide a few computers in the office area for campers to use (with restrictions) and that would be it.
Tim