Well I had pretty good luck with the underarmour as long as I kept moving. But I am trying to source some merino wool baselayer stuff for what I think will be a better setup. Had a flat today that I couldn't repair and wound up waiting about 15 minutes with temps in the teens for a pickup. Started to get pretty chilled by the time I got picked up. Could have been worse if I was farther out (ride in a real rural area).