I had to resurect Astarion twice. Once in the Underdark, when something pushed him to death, second time when the hag pushed him into the chasm.
Both times, Astarion bugged out on me. First time round I rerolled to a save before he was dying. Second time, this isn't an option, since too much time and too much quests have been solved. Astarion returns to camp on his own and the camp location doesn't change. It stays as it was when Withers did his job.
