I chafe a lot, so I'm pretty specific about the shorts I wear. When it gets cold I tried switching to tights but I found that no matter what kinda tights I was wearing, I still got chaffed pretty bad. I even had runs where pubic hair from my left leg got tied in a knot with pubic hair from my right leg.
The last 2 years I have just been using my summer shorts, and I just put loose sweats on top of them. It worked from a chafing perspective, but they were heavy, and picked up a lot of slush from dragging on the sometimes snowy trail.
This winter I will do basically the same thing, but I got slightly nicer running pants since the sweats hit end-of-life.