The BIG trouble I see is that after several years of work you might get kicked off the land you are squatting at. That would be a tragedy!
As for greenhouses, my husband talked me into a kit but I regret that. Honestly, if you can build a frame of pressure treated wood you can make hoops of plastic pipes and then fasten a plastic greenhouse cover over it. Have you read Elliot Coleman's books? He raises vegetables for sale in Maine in a similar manner, though I think he uses metal hoops instead of plastic.
We have had a few nights in the single digits, and I still have beets and onions in mine. I covered the growing beds with cheap plastic paint tarps when it got very cold, as Mr. Coleman advized, and it works a treat! There is very little new growth during the winter, but the vegetables stay in excellent condition!
You might want to drift by this area:
http://www.unitedcountry.com/search06/SearchViewProperty.asp?SID=129524735&Item=773647&Lcnt=&Page=1&Office=36059&No=36059-78487&AU=N&FT=P
With prices so low, I suspect that there are not too many people. Just guessing. On an ealier page it says they were wanting $10,500 for 9,85 acres.
http://www.unitedcountry.com/search06/SearchResults.Asp?SID=129524735&Lcnt=&AU=N&RF=N