Howdy;
I know this is an old thread, but today's my first day here, and I've already asked a favor, so I figure I should contribute something.
So, I agree, the trifoliate orange (Poncirius trifoliata) would be a superb barrier choice. It's been used as a barrier since Roman times and was particularly popular in the eastern American states during the Revolutionary era. The fruit is lousy tasting, but some folks manage to amke a palatable marmalade with it.
The big Miscanthus species might work, but that's not my favorite idea.
Opuntia cactus is another really nasty customer that grows great with no supervision. One of the benefits of this is that it's free, as long as you can find someone else already growing the stuff. I'm not sure how much is growing in your area, but if not, it's a cultural situation, not a horticultural problem. Most opuntias will tolerate a fair amount of snow.
Regular bamboos, like phylostachys, bambusa, isn't much good as a barrier. True, an established stand can grow prodigious canes in a season, but it's hardly ever thick enough to retard a person who wants to pass through.
