Friends, REI just sent me a pair of Arc teryx SV Theta bibs (and I sent them more than a few coins). They are beautifully made of the latest Goretex Pro material. Very light and fit me well. But they are a shell, no doubt. The other pants I have are insulated. Usually, I am comfortable with a pair of CW-X insulated longies, or something similar. But I think more might be necessary for a typical February day in Maine when the temps are at or below zero and 20-30 mph winds. What are good options for serious longies?