FWIW, with the bosses in the temple the chief issue came from them summoning allies as soon as they were attacked, so I made sure that no one was there to answer the call. There were still some goblins in the front of the temple, and when I returned they too were hostile, but there were a lot fewer than eighteen of them and they posed no problem. Minthara just died after I threw a caustic bulb at her; she and her minion just stood there taking damage and speechifying until he eventually died and she was one-shottable. That's probably a glitch. Never had a talk with her; the nifty amulet of speak with dead I have did no good. Only one that posed a problem at all was Ragzlin, and that mostly because he couldn't be separated from his followers.
One hint is to always destroy any drums you see. Is there any way to save the goblin in a cage who preaches about his loyalty to Wossname? I have a cage key to let him out, but every time, Astarion would fail to see a trap and we'd end up taking massive damage, and the goblin died.
