Overnight without the kids?

I think you have everything covered! To you it seems like you will be away for such a long time...in reality it's just overnite, they will be fine. Even if you didn't pack ANYTHING at all, they would still be fine....they have stores where your sister could get diapers if she needed, clothes if they needed extra, and food. You have to trust that your children are in great hands and they will be fine. Go have a great time with your husband ( I am jealous by the way of your getaway! ) and try to relax and actually enjoy yourself. When you get home and pick up your little ones you will see that you worried for no reason and that everyone was fine and actually had a good time. It's good for the kids to be without you sometimes, it's like an adventure to them, something different and they get spoiled by their aunties which is nice for them too. Your a good mom for worrying so much....i would worry if you didn't worry so much!