Its more important that you have warm air getting removed from the room, than that you have fresh air comming in...
dont dump the warm air from your lights back in your room
I would try to have a passive intake to another room in the house if you can, not from the freezing cold outside air... otherwise just vent out to your attic with no intake. You will create a negative air pressure in the room so that air is sucked in thru any little cracks and gaps