Hello everyone. I'm cooking for my son's graduation party this weekend. I'll be doing 2 briskets and 8 slabs of ribs. I'll be starting the briskets early in the am with the ribs to follow . My question: how much longer will it take to cook 2- 17 lb packers vs cooking just 1? I'm planning on throwing them on at 3am and hoping to serve by 5pm. I recently did a 17 pounder in 10 hours, holding it at 160° for 5 hours then slicing. The absolute best brisket I've ever cooked. I'll be smoking at 250°- 260°.