I'd have to visit your thread to get a better idea of what exactly is going on but I will say that h should either spend the night to wake with the kids and help them get ready for school or meet you all at home and get to the bus stop together. Imagine how odd it would be for the children all waiting with the OTHER children to go off to school to meet their dad their...their excitment over the first day AND seeing their father will be too much...if they can be gretted by him at home first that would be better. Since it doesn't sound like he'll make this suggestion YOU SHOULD. Of course without expressing care for what they other children will think..simply make the suggestion that he either spend the night or arive at home early to all go off together. And don't forget to thank him either way (for coming early or meeting you there)
As far as what to do while he is gone? keep yourself and the children occupied but it also sounds to me that h wants to be wanted home by you...why not initiate a special night of the week for the "family" (Pizza and game night) and invite him to join you all.
