I've never tried filling a condom with water, but unless it was from a running source, like a little spring etc, wouldn't it be a hassle to fill from a standing source :question

I'm wondering if a quart freezer type zip lock bag might fit in that kit.
Folded flat, it shouldn't take up much space.
Easy to fill and tougher than a condom to be sure.

I have a stainless steel emergency drinking cup, that folds flat. When opened it looks like an old school pointy bottomed paper water cup you used to see around office water coolers. I have it in somewhere in my gear room, just can't recall location exactly ;D When I dig it out, I'll see if I can find mfg. It might fit in your kit and you could heat water, boil critter soup in it with a little effort. I've had it for years, but a Google search turned up 0, so maybe it's no longer made.

Nice effort. I think we could debate choice of contents till the cows come home, but the important thing is your being pro-active, instead of re-active.
Plan for the worst, hope for the best is a good motto for the wilderness traveler ;)