I think that the amount of moisture in the air and dampness of the vegatation can affect how much your scent stays on it for how long. I think colder air will inhibit animals' ability to pick up scent. At least that is the case with hunting dogs. Very dry and windy or very cold and dry cuts down the amount of scent that stays on grass and other vegatation as game birds pass through.

However, I think that deer, Elk and animals still have extraordinary sense of smell of what they know is danger. So, I would count on cold alone to prevent them from busting you. You still need to avoid the obvious (e.g being up wind, smoking, other human odors) as much as possible.