I freeze mine in the plastic ziploc dishes-type things. It keeps a long time and reheats well in mocrowave. Ziploc freezer storage bags are good too, but it gets messy getting the juicy pulled pork bbq out once heated.
I freeze almost anything in vac-seal bags. I do pulled pork in 2-lb paks. If ya want to eat some, figure 1/4 lb per sammie for however many people, pull out how ever many paks you need. If ya pull out too much (is there such a thing?) ya got a little leftover for tomorrow!