I have that coat and it is very warm, if anything for 20 degree temps and less wear another woolrich wool sweater under it and sub layer any sweat wicking long sleeve under that,,,, I've been out at 14 below wind chill with that setup and yes the wind dids somewhat make it thru but it was comfortable,,, 20's and 30's no problem!
watch the sleeves though, I usually don't wear armguards but need to with these old woolrich coats because it gets baggy up near the elbow for me and thats thinking of hunting type shot angles where I might have to lean off the stand and turn at the waist a bit.