Interesting, and a bit strange to read and hear (in media) about B-1B to use bombs in case the situation with NK goes that far. Why not cruise missiles from ships or subs (or the same B-1B) some 1500 miles away with no risk of entering the reachability zone for SA ground complexes?
NK planes seems to be not a serious issue in this bad scenario because all the air strips would be damaged in a couple of days. But C-300ПТ (SA-10) presumably shipped from Ukraine long ago and recently built KN-06 (using Chinese technologies) would be a more serious threat.