We are often camping at, or just below, freezing. At these temps condensation becomes a big issue for us, and even with the furnace running some (we set the temp at 9°C) we begin to get condensation, but the air in the 19 circulates around the bed fairly well. We do keep a vent cracked, but do not open the windows too much, as we don't want to lose too much heat, and have the furnace run even more.
2017 Escape 5.0 TA (someday soon, I hope
2015 Ford F150 Lariat 3.5L EcoBoost
2009 Escape 19 (previous)
“Most folks are about as happy as they make up their minds to be.” — Abraham Lincoln