I learned that the hard way back in 2003. I took back roads home from Burlington through Cambridge onto the X way in Feb with a surprise snowstorm. That was about 5-6 hrs, coming home from UMass Lowell. Should have stayed on 128.
That slipped right down your fanny crack into ern MA. You were like 12 degrees when I was near freezing for a bit. We then cooled off at the surface as it warmed aloft.