Opinions regarding improving WiFi at campgrounds

WiFi and cellular are two totally different types of signal. They do not interact and cell phone companies do not provide wifi capability (yes, verizon used to have local hot spots, but those have been discontinued).

to Clarify a bit more

that was 'local access' thru a National supplier/isp (a contract service)
in other words, access at coffee shops etc.. provided by your Verizon contract
who made a deal directly with the service provider