And I'm finished! It was a lot easier this time, although I did, er, not so much cheat as "maximise my opportunities", mostly reloading to make sure I got weapons with a good freeze stat.
Josephina continued to be the biggest headache, though a much diminished one this time through: a combination of shadow potion, the aforementioned weapons and a twirl attack were enough to deal with her. I had used Flash Attack to sometimes good effect in my previous game but couldn't get it to work with my warrior build, curiously.
So I think I've done everything, including the slight shenanigans to get to the Larian Prison.

I understand that the pyramids can be thrown into otherwise inaccessible areas to explore them too, so I may do that now just to finish off.
Maybe I'll continue Beyond Divinity next, though it's not so much "that voice" that's putting me off as the excess of awful grey-and-red landscapes: at least only the northern bit of Luculla was like that in D:OS but there's far too much of it in BD, I think.