We have spoken to parents with kids who have also been considering this issue. A response in many cases has been that they approached the school which the child attends and have had session packs prepared for them... the children then do these at times which fit with the travel schedule.
Some have also kept diaries and undertaken maths and spelling type activities as part of these: fuel use, kilometres travelled, distance between towns, costing of different items in different places, etc etc etc. Even interactions or observations produce much knowledge.
I believe children learn so much about life and living while travelling that the educational experience is far greater than what can be learned in a class room.
There is also a distance learning school in Victoria.
http://www.distance.vic.edu.au/ which may be of some assistance to you...
Regards,