That is some seriously cold weather Dan!

I don't know exactly how much cold effects a deer's nose. I know that I am just as careful of my scent, if not more, in the late season. The average temp during that time is somewhere in the mid 20s. Most of the deer I see are in the evening and usually all of them are coming from a specific bedding area. Most of the time I see one group of deer the last 30 minutes of light. If I spook one deer in that group, my hunt is likely over for that evening. In October and November and I can see deer at anytime and they can come from multiple directions. Spooking one deer won't always mean I won't see another. In late December, spooking one usually means spooking all the deer I was going to see that sit.