I've tried about every method you can think of, when it comes to keeping/reheating butts, and have found (what I think) works best:
1. Take it out, when done, double-wrap in HD foil, as usual.
2. Rest for 1-2 hours in the cooler, covered with towels.
3. Remove from cooler, and while still wrapped in foil, seal inside a FoodSaver bag. Fill the kitchen sink with ice water, and drop the sealed butt in there for a quick cool down (because it's still really hot). This prevents spoiling everything in your fridge, by not putting a 190° butt in there, and will definitely keep your better half happier!
4. When I get ready to reheat, I take it out of the vac bag, and put the wrapped butt in the crock pot on low. I give it 3-4 hours.
5. When you unwrap it for pulling, it's just like the day it was smoked, and plenty juicy!