My two pence,
If you are asking can the entire family go.. the answer is YES.. go like Wilky said.. your child will be the better off for it..The real education and experience he will receive will only have one negative side effect.. Travelling is addictive... As for schooling (I lecture in a university) a home school (HS) kid that has travelled and seen the world could not be worse then some of the students i have now...
(this could even be true if the child was educated by a couple of dyslexic/mute/deaf/illiterate/innumerate parents- not saying that your two are- just schools are not all that great these days.. ). In fact I have a couple of HSers and they are getting the top marks in the class. Now if you added in real world travel and these kids would be amazing.. (if anything they are a bit sheltered and shy.. but this is just this brother and sister pair, not necessarily HS's doing)

If however i am reading things right your husband wants to go off alone.. then bugger him.. it took two to make the child he HAS TO HELP. If the relationship is not working fine get a divorce but he still has to be around and give money.. you should not have to raise the child alone and support his travels.. that is just not right...
Kids are not a choice you can unmake.. so he is suck with his choice for an other 10-12 years... Sorry mate that is the way of it.. Going off travelling will make him a deadbeat dad.. his child will grow up not knowing him..

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2000 Africa Twin
http://two-up-ona-twin.blogspot.com

Having played some part in creating two children I feel I owe it to them to be around and support them until I'm no longer needed. I am currently (probably over-) planning a trip we will undertake as a couple when our youngest leaves school.

We have thought about HS on the road, but both Mrs MarkE and I know a few forces brats and their experience meant we wanted our children to have a stable home life when they were young. Among those we know (perhaps not a representative sample) there are a lot of people who suffered from too many moves too young. Their schooling (in terms of exams passed) may not have been harmed, but some do show scars from not having had the chance to forge real friendships in schools. In these cases they were moved before they settled and made those friendships. We may be jumping to a false conclusion, but these are my children we're talking about here, and I'm not prepared to gamble.

In the meantime, both Mrs MarkE and I have made a few shorter trips, together and solo; grandparents are wonderful, then when the kids are older sleepovers are good; being such wonderfully well brought up kids (ahem) they were as reliable as any teenager, which meant we could leave them overnight sometimes. The elder has now left for university and, last time we left her sister alone we came back to find the house still standing after five days (far more sensible than her father then). I've got two more sets of exams to hold her hand through, then she too will leave, and we can take off for a few months trip.