Pond Boss Forums INTRO Questions & Observations F1 cold tolerance, how far north?

I have been interested in the possibility of stocking F1's but realize I may be a little too far north. I've tried researching how far north is acceptable but am finding very little. I see a lot of talk about the F1's being more cold tolerant but no specifics. I did hear rumor of them being stocked somewhere in New York state but haven't found anything more on that. New York state is actually further north than I am so if they had good results I would be encouraged. I get the impression not many have tried to push the limits and see how far north the F1's can be successful, but I'm sure a few of you have. My thinking currently is why not try it. If I could stock 50% F1 and 50% northerns and even if they only lived a few years I would have (hopefully) introduced better genetics to the pond. If they do die I've still got the northerns to fall back on.

And let the games begin....