Verizon provides 4G access at the most locations across the country. The more remote the area the more likely that the only reception and data service you will get is with Verizon. Second best in terms of coverage is AT&T.
With their Mifi device you get 4G data access and you also get a router so that 10 computers and cell phones have simultaneous access and you have a mini-firewall. Using a smartphone as a Wifi access device is actually pretty dumb as there is zero protection from someone connecting in a second and gaining access to everything you have on the smartphone.
With a mifi you have a secure connection to the internet and also have secondary firewall protection from the computer's operating system and any anti malware apps you have installed.
The ONLY time I access a campground Wifi is to download and upload email. It is not safe to use for web surfing much less financial transactions as it is PUBLIC. All the campgrounds I have visited and most hotels as well, do not change the password and often they even have sign posted stating the password so the office people will not be bothered or to provide it after the office has closed for the day.
I would check into Millenicom.com. Although they have been acquired by Verizon they were still selling service to the Verizon network and Mifi devices. With Millenicom you may be able to get service without a contract and their data usage tracking has not presented the problems that many Verizon customers have been burned by and commented on at the Verizonwireless commmunity forum.
