How big of an advantage would the cold weather really be for teams in colder climates? I randomly came across a football freakonomics article which seems to imply that it may not be the advantage that people typically make it out to be (thanks Flipboard for keeping me entertained in class). Okay, you might say, it could be in large part because of things such as heated fields and benches that not all NCAA squads will have access to. That would still imply that a cold weather college kid would do better in the cold weather, right? Wrong.
We also wondered if cold- and warm-weather teams draft players based on whether they played at cold- or warm-weather colleges. In short, the answer is no. (See the graphic for details.) I guess with the multitude of factors that teams need to consider when making a draft pick, the question of whether your guy is more acclimated to heat or chill just doesn't register as very important.
So players just deal. Which coming from the more temperate climate of NC to OH, I can personally say while it was a rude awakening, it was managable and I've more or less gotten used to it (granted I don't have to compete athletically outside in front of thousands of people). I also remember players such as Favre who would actually thrive in the cold, despite being from the South and even spending his off seasons in his home state. Unfortunately I don't think we could make a side by side comparison at the collegiate level, since I can't think of any SEC squad that's ever made a trip north in say October to see if this really does translate to the collegiate level. Looking at the D3 level, two of the squads that have the best conference records are the Ohio Athletic Conference and the Wisconsin Intercollegiate Conference, but it is hard to say if this isn't due to any number of other factors. Given regionals are limited to a 200 mile radius, I doubt the weather would be much of a factor given they both come from the same climate.
All that basically to say, I don't think weather would be a huge factor. Not that it would even be something to consider in our lifetimes, but we all know snow can't stop eS-EEE-sEEE SPEEEEEEEEEEEEEEED.