I agree with campground WiFi being unreliable. I also worry about how secure it is so depend on my "JetPac" from Verizon.
On this last trip, we stayed at a CG that had free wifi BUT you had to create and account, log in with account info, use their password at some point and were limited to 2 hours 2/day. UGH. That's too many clicks, IMO.
A lot of CG reviews on rvparkreviews mention the WiFi signal strength now. I wonder if you specifically ask for a site with a good WiFi signal, if a CG would try to accommodate?