I think it'll be fine as long as your husband can sleep on Friday during the day. He won't have the kids to look after while you're working will he? My biggest concern would be feral kids the next day if they don't get the same quality of sleep in the car! Also, when your husband works nights does he usually have someone working with him to keep him awake? I work shifts, but with a partner to gibber to when I'm tired! And are kangaroos a concern on the route you'll be taking? I know it sounds ridiculous, but there are so many accidents on rural roads at night when there is not much traffic and the roos are bounding around!!