Ditto on defatting the drippings (if you can catch them) and adding before chilling. Never used a true finishing sauce myself, but the drippings added in make a huge difference. BTW, if you add the drippings, when you remove the package from the fridge, you'll find tons of geletin from the juices...awesome stuff in there.
To reheat, keep it low & slow as when smoking, and I like to have a layer of meat no more than 2" deep...this will get you through the danger zone temps in good shape. I also use my digi probe when reheating larger quantities, just for my own piece of mind. Anyone that will be eating your fine table-fair who notices the temp probe (and knows why you're using it) will appreciate your care for their safety.
Have a great meal, Brian!
Eric