Can you actually go outside in MN during the winter?
I enjoy running in the winter much more than summer. You might see your times get better too.
As far as what to wear, I really recommend staying away from cotton. It's horrible and it chafes. The technical gear will really be much more comfortable. Depending on the weather, fleece is great to keep warm. It's important to layer. You might want a wind layer to wear over it for windy or rain/sleet/snow. You can get tights, but they do make more flattering loose pants. I have waterproof pants that might actually be for cross country skiing on really wet days. Although, at the point when it gets really snowy or icy running becomes pretty difficult and it's better to go inside on the dreaded treadmill.
Good luck in your half training. It will be great. Sounds like you are a quick one.