When I re-heat BBQ I wrap them in foil and turn the oven on @ 250.
If they're too wet I open the foil and let them dry out in the oven for a bit. Takes some experimenting to find what your idea of optimum is.
Once you got it down it's a good way to hand out gifts around the holidays. Frozen brisket or ribs or whatever and the directions.
People love that schit.
Travis