I have fired my Glock 26 at temps of around 15 degrees F. It shot fine, I will not comment on how accurate it was. I was shivering badly. I do not do cold well after having hypothermia twice the cold is not the same anymore.
If properly maintained either will work in cold or hot weather. Pick the one you shoot the best, or like to carry the most. Chances are it will be on your person more.
No matter how many times you do it and nothing happens it only takes something going wrong one time to kill you.