I'll take 1 week drive to Cairns with the camper trailer and pick up the balance of the family there.
We'll take 2 weeks to drive to the tip and back to Cairns. Family will fly home and I'll drive back.
To make the drive to Cairns interesting I'm hoping to go via some places of interest like Longreach to check out the Qantas museum.
So far I've mapped a few alternate routes on OziExplorer and used Google Earth to check the terrain etc...
We have two other families interested in coming with us - hopefully they too will be able to arrange the time off.