Ever considered a vinyard?
I have a friend who is a major homebrewer, and he has a vinyard in his background. i enjoy homebrewing, and I recommend that you give it a shot.
Try to focus on reisling and chardonnay and other white wine verities. On land like yours, you can get very, very good yields. In fact, with the climate in your region, you can even try to pull off ice wine:
http://en.wikipedia.org/wiki/Ice_wine