The best nearby airports are:
Williamsport, PA 1 hour away, nice local airport. Not a grass strip.
If you don't mind going through NY state, Elmira, NY is about 1 hour north, about the same size as Williamsport airport.
Biggest and best is Rochester, NY, 3 hours north, and 4-lane hwy most of the way to Wellsboro, but its in NY. Those are the options. No need to go to Harrisburg, as its not much bigger than Williamsport, functionally.

I will connect with the Whitneyville fairgrounds people. There may be other options available. Can anybody give me a rough idea of the dimensions of a space we will need? X feet by X feet for example?
This is all good, and any and all help (offers to show up early, etc) would be much appreciated.
Bob