OMG, I saw this title and my younger sister & I used to have crazy discussions like this back in the day!
Most recently, I asked my husband something like this one day after we watched an episode of the Walking Dead. He asked me why he would want to survive the apocalypse? Honestly, I think he thought it was way too much work. Anyway, good question, but for the purposes of the discussion I wanted to know. Luckily, he's fully prepared to go on a moments notice so we are good to go!
Now, to the topic of this thread, I would absolutely take 2 Longchamp le Pliage totes--a large, long handles in a discreet color and a medium, long handle tote (in a bright color so I can find it easily) folded up inside my main tote. You never know when you're going to need to scavenger for supplies, so it's good to be prepared. I'd also grab a bum bag for essentials--Advil, crazy glue, spare contact lenses, etc.).
As I'm reading through this thread, I really feel like I need to pick up a nice, lightweight backpack. It seems like that would be handy in this type of situation.