You might want to look into the Wonder Bag

http://www.amazon.com/Wonderbag-Portable-Cooker-Recipe-Cookbook/dp/B00ESI97YU

Never heard of it until now. Here's a link for other interested parties.. There are a ton of first-hand reviews on Amazon, too.

I wonder if something like this Wonderbag might work for you. You don't have to worry about turning it off, because it is not really on. You heat up your food first, and it insulates it and allows it to continue cooking for up to 12 hours (according to the description and reviews). I don't know why you couldn't use it with your existing cookware (not the crocks, I mean, but other pots and pans). Storage would be easy because it's just a bag.