I made the mistake of leaving a foodsaver bag full of frozen smoked pulled pork in water until it boiled.
It was the morning of a planned party, I got distracted, bag came open, lost about 10 lbs of meat. I almost cried but fortunately I had an extra bag, watched it like a hawk.
Basically I vacuum seal BBQed goodness without any sauce, freeze. To reheat, before Sous vide, I'd bring water to a gentle simmer, take off the heat , drop the bag in and cover the pot. If water gets cold, take the bag out, reheat water and repeat.
With sous vide, heat water to 135 and drop bag in until I'm ready to eat.