I would find it highly unlikely that even the bus company will be able to tell you what time to expect the bus for September. They arent even at the stage of planning that yet. If the bus stops at the bottom of your driveway as you said, then I dont see that it would be that difficult to work into your day even with the other little ones. You wouldnt have to walk anywhere with the younger kids and if it is raining then I would be inclined to co-ordinate afternoon snack or a brief period of colouring or tray play so the kids can sit in highchairs and be entertained safely while you grab the other kid off the bus...that is unless you have a rediculously long driveway ;-)