You could do what I do on the rare occasions that I venture out with both children - get one of those carts with the car attached to it.  Boo thinks it's the best thing ever to sit in that and the Bug just hangs out in her car seat, cooing and gurgling at passersby.  However, make sure you frisk the toddler before leaving the store - they keep strange things down there at toddler level.  I wound up buying some ramen noodle thing because Boo had peeled it open and started eating it while I was obliviously loading up the cart with real food.

Good luck on your week away.  TCBIM went away for a week shortly after the Bug was born.  Not a lot of fun, really.
