So I have a 13.5LB brisket to cook for thanksgiving lunch at 1:00 and i was planning on starting at 11 PM wednesday night. The issue is the temps are gonna be down in the teens at night and mid 20's durring the day. Should i be ok keeping the temps in the 220-250 range? I was planning on starting with a full chimney on top of a full load of unlit. Usually i start with about 20-30 brickettes but I am thinking i will need the extra for the cold temps. Any advice would definetly help!