Which save do I have to reload for the epilogue?

I keep seeing "the last save before the final boss," but that could mean a few things. The high hall before entering the final fight? The morphic pool? The undercity ruins? I've also reloaded my quicksaves during the previous ending (the scenes where Astarion runs off when he starts to burn in the light, Karlach burns up, etc.), and nothing happens after that point.

How will I know when I've done it right? I've made sure that I don't have any mods installed and I've verified my game cache. Will I automatically be sent to the afterparty, will I have to manually go to camp, or what?