Hey, I'm only a week ahead of you...I've been buzzing for about 10 years (I'm 45 now), and I finally decided to go all the way this morning. I'm also in Wisconsin, and I was a little worried about the pasty white thing as well...I finally decided I'd be happier with a little two-tone action than waiting another four months to finally shave my head. That aspect of it actually isn't as noticeable as I thought it would be. My advice would be to go for it! I think you'll notice a bit of a difference without a had outside, but it's not going to be a huge one. It's supposed to get to -30 tomorrow, and at that point anyone without a hat is pretty much kissing his ears goodbye.
Good luck!