A good source of info for you would be Dr. Mark Cornwell's (of SUNY Cobleskill, IIRC) articles in back/future issues of PBMag. He has a lot of experience with NY waters and has a pond at a fair elevation there at home.
I think I've seen ice on my ponds about 3 times over a lot of years. No help here.
Two of those times were when he dropped a cold drink into the water.
