I have found that for most meats, you can reheat once successfully. After that, it goes down hill fast with each reheat. So I package single serving sizes in zip bags, each with some au ju or foiling sauce. I keep a few in the fridge and the rest in the freezer. If it's just a little bit, like for a sandwich, I open the bag a nuke until warm. 45 seconds for my nuker.
Steve, what really works well is a vacuum sealer, I used zip-loc and a straw for years You wont regret a sealer