Just spent this past weekend away in the Rocky Mountains with night time low temperatures in the 4 to 6 degree C region (39 to 43 deg F). With furnace on most of the night, we had windows shut first night and moisture built up quite a lot on the windows. On second night, we found that with 1 or 2 windows cracked open, there was a significant reduction in moisture buildup.
Dave W - 2013 Escape 19' and 2011 Toyota FJ Cruiser
"When you arrive at a fork in the road, take it." - Yogi Berra