Well you have two options
Option One which we will call the what I would do option - Keep it simple, make sure they are feed and washed and happy, anything eles is a luxury you can't afford. After all your wife can clean and do laundry when she comes home
Option two which I will call the Canadian Army Option - Call your mother or Mother in law.
I have been there and made it through -barely - my girls are as crafty as the Tailban and food gose through them like crap though a goose. When they look me with love in their eyes I know they are getting ready to stab me with something.
Good Luck your on your own!
This link might help
www.youtube.com/watch?v=5PokBAxtvW4