Finally got the solution to smoking brisket or for that matter cooking with coal up north. Lurking on a BBQ site I read about using a welding blanket to help keep the temp constant. So I figured why not give it a try. Bought a welding blanket on Ebay and it friggin works like a charm. Use half the amount of coals and it keeps the temp constant. I started at 6am this morning when it was 45 out side. Had it up to 225 by 6:30 and with some minor coal and wood additions sat between 220 and 245 til 12:00 before I moved it into the oven.