true story, While in the Army, my platoon spent a night in 2 person tents, in 15-20 degree weather. Next morning at o'dark thirty, we were roused by the NCOs to get moving by dawn. Ain't nothing funnier than 30 guys trying to fold up frozen tent sides while being screamed at by Drill Sergeants. I'll never forget the confused look on some of those guys faces when they picked up the canvas sides, solid like plywood from the condensation.
moral of the story: even 2 people make lots of condensation. And always allow ventilation at all times.
2000 Cherokee 29BH with 6V batteries, LED lights & 400 watts of solar power, flipped axles and raised. 2007 Tundra 5.7L DC-LB with lots of mods. C-co, 8/158th AVN Maint.