kylewayne does not post much, but lurks here sometimes. He can answer that, having shot unbacked osage bows in Noatak, Alaska at -45 degrees F!!! If a bow was going to fail due to cold, one of his two would have done so because on neither bow was the tiller exactly perfect. I am not disparaging his bows, and I can be forgiven for being critical of the tiller because I made them.
What lets go first is not the bow, the string, or the arrow...but the archer's will! If you can take it, the bow can take it!