The World Off Road
There is also an interesting project of a Greek couple. They did a 3,5 years RTW trip (2007-2010). Then they had a baby who is now 5 years old. Now, they are about to start another RTW and homeschooling will be part of their daily routine. They also have an interesting survey about homeschooling & long time family travelling.
Check them here: theworldoffroad.com