I bought what I thought was two butts but after looking at it I realize it is one huge shoulder just under 21 pounds. I want to serve dinner tomorrow night at 6pm or so. Should I cut it in half? Keep it whole? Start the dang thing this evening? Ive never cooked a piece of meat this large and not sure how to progress. Cooking on an OKJ modded with door seals, firebox is sealed, charcoal basket and tuning plates. Holds temps well. I also have to leave for about 3 hours in the morning but not to worried about that as I can stock the firebox before I leave and it should be fine.