Thought I'd post an update after a year using my setup - and as I begin another 3 months 'remote' from my normal home office.
My setup (a PicoStation2 to connect to available wifi as a single device feeding a linksys router that provides local wireless inside the RV - my PC and other devices connected to that) has worked great for the last year... The only caveat is the reliability of the campground wifi - but with the Picostation on top of the TV antenna mast - even if the closest hotspot is having issues - I have typically been able to connect to another in the park. My fallback is still a hotspot on the phone that the whole network (or just my work laptop) can connect to in a pinch.
I have not found a reasonably priced 'unlimited' means to actually have a full time hotspot in the RV - so haven't gone that route yet.. If anyone finds a deal - let me know..
Just got back to our winter home - and they did fix the wifi... of course added a charge for it now - but after connecting the picostation to the closest of the 3 towers it could see - the connection has been solid... How solid? well - the wife got a PS4 for Xmas... and first thing she did when we got online was download a 14GB game - not taking much longer than it would have at home (wouldn't want to pay hotspot data charges for that one!)
RV network supporting 2 phones, 2 tablets, 2 PCs, Bluray player in bedroom and PS4 in living area... with no complaints.
Sites wifi is thru Camplink... Wish the cost was a bit less 3 mon about $120 - but so far impressed with their service. No advertised bandwidth limits - and no complaints with my usage thus far.
Comcast cost about the same last year - plus a bunch of setup issues with site and RV cabling for which they wanted to charge me much more...