Originally Posted by
duffetta
I used to wear something similar for xc skiing with plain PI tights. Then I found PI Amfib tights and biking [loose] tights. Both have a windproof front and breathable back. The loose tights (performance) are good on their own (only skivies underneath) down to ~20 deg F.
The OP should wear something similar, then change into the casual pants at work.