First, pork shoulder is fine at a higher temp. It's also fine at a lower temp. It's pretty forgiving, but I generally go hotter.
Second, I always smoke everything way in advance and then hold it. I calibrate my oven down to make it a warming drawer — as long as the temp remains above 140 it's safe. I shoot to hold it around 170. I'll even make things the night before and reheat day of sous vide. I actually find that this allows all the flavor to permeate deep into the meat and gets really good reviews.
The final product looked great so this is more about nailing the timing and reducing stress.