In my opinion, both you and your W need to stop the whole idea that you can just take your kids and make a change without informing the other parent in advance. First, your wife up and leaves with your children. She was completely in the wrong. Now you are contemplating picking up your kids and once they are with you saying "oh by the way, you wont see them for a week because I said so." In my opinion, you would be in the wrong.
Please stop this behavior, it is so childish and not in the best interest of your children. In my opinion, you need to completely eliminate the entire notion of making unilateral decisions and then telling your W after the fact because you are scared of what she will say.
If your wife says no, then you call your lawyer and legally pursue a resolution.
