Another problem might be how you dress on cold days. If you cover up
your mouth and nose with a scarf or neck tube or whatever, then you're
going to tend to fog your goggles more.

I agree. I use one of those face masks with the nose and mouth molded
in (like some models that Seirus makes), and usually don't have a
problem. I am not the most stylish guy on the slopes, but it works
well for me.

Jack