Pork Butt Disaster

it all varies depending on the butt! Last week I cooked 2 9#s and one came off in 12 hours total, other stalled for a  17hour total.  Figure 2 hours per # overall cook to be safe. That usually gives you rest time. I personally try to allow for 2hrs/lb and 3-4 hours to rest. That ensures you plenty of time and resting. It doesnt hurt to pull and chop it then refrigerator after it cools, reheat when ready to eat. BTW quality lump is key in temp and taste