I am not sure if this is a viable option in your state as far as the law goes... can you assign a temporary guardian for your children (friend for example) if your wife is out of town and something would happen to you?
I made my sister my health care proxy in case I become very ill and unable to make medical decisions on my own. Technically my H is still my next of kin as we are legally separated and I did not want him involved at all. Is a similar option available to you regarding temporary guardianship?
I am not 100% sure about this but I *think* if minor children do have a next of kin that just happens to live far away they would not be wards of the state while the next of kin is traveling.