Too Cold

It's too cold to do my pacing on the porch to get my steps in on fitbit so I'm walking inside.  I'm not nearly done, but at least I'm getting some steps in.  I can bundle nicely for the arms, neck, and torso, but my legs just get too cold.  I'm thinking what to do.  I think maybe leggings under polartec pants would work.  I have the polartec pants, but I wore the leggings out and tossed them a couple of years ago. What was I thinking?