You might want to contact the local university or county extension office. Plants with improved weather resistance get them very excited. You might even get it named after you.

-Blast, who is still looking for that damn avacado tree some rig hands said they found growing in a snowbank up on a Mexican mountain.

In baggies. A quarter-ounce at a time?

haha

From what I've heard, they are hardy down to about 0F, maybe a bit lower occasionally. In MN we regularly get well below zero, occasionally down to -30F. If you're getting that, and your trees are surviving, I think I'd like a few cuttings please!