The vent holes will work. I leave my two small vents open on each side near the roof, with the door closed up. Anytime, I go outside to check a tipup, I leave the front door open to ventilate, until I get back. After I get inside and zip it up, it heats back up quick. Also, if the heater shuts off, open the door for a minute or two, zip it back up and turn the heater back on.