Hi Edmund... I'd leave in the foil and place in an oven at the same temp you smoked it at. If you want to make it moist, put some liquid (apple juice or even a bit of water) before reheating.
I always pull pork butts at the end of any cook whether we eat it or not it makes for a better reheat But I would think put it in an oven at 200 bring up to temp 160 then pull it.
