A practical forester I know, who is a serious hunter uses 2 tents. The 'inner' tent is a packable dome and when the weather demands it he has a modified larger dome that goes over the whole shebang with significant air gap between. He claims tee shirt comfort level with a Buddy heater down into the teens. Like all plastic tents and propane heat and cooking, he says moisture buildup is a constant battle between adequate ventilation and warmth.
