I agree with everything that's been posted here. Converting farmland to commercial property likely comes with all sorts of challenges/implications, and opening an RV park has even more on the regulatory side. Given your distance from the Thruway and lack of local POI's, I think it's an uphill battle from a marketing perspective and HUGE risk as far as a reasonable ROI. While they charge a bit more, Turning Point is only 30 minutes up the road, has all sorts of amenities, and is right next to the interstate - that's a tough competitor for the overnight stop.
If I were you, I'd stick with Harvest Hosts for a while to see what kind of traffic you get before jumping in too deep.