If you go to the Inn, they're listed as "Dead in the maze" - is there a way to recover their bodies and take it to the temple? If so, I've not figured it out - went to the room they died in (was on the first floor so not that difficult - down the stairs, immediate right, that room a few clicks down on the left). And when I walk around the room with a single new character, there's nothing?

Okay, yeah, this one isn't exactly intuitive--there was a separate "Inspect" or "Search" command for this in the original version.

But anyway, to (try and) find your party members, go to the room they're in. Open Camp. Then open the Party menu within Camp. From there, the game should tell you how many characters are in the area and you can add or remove them freely.

Do note that there is a tiny chance the characters are simply lost forever. Since you're on Floor 1, it's extremely tiny...but if you're dying on Floor 1, there's a decent chance you'd be better off just re-creating the characters than trying to revive them.

Hope that helps!