The biggest problem with that is finding space for all the craft 'stuff' that you need.
I've already made plans for room for my two sewing machines to come along but part of that is because I make most of my own clothes. I need to break my habit of saving the leftover scraps though because they quickly add up to mounds of fabric.
Soft toys in particular require large quantities of stuffing to be kept on hand...
(Don't ask me how I know that...
) And multiple large cones of thread in every color on the rack at Joannes...
What you can take with you will depend entirely on how much space you have to devote to it. I'm lucky I have a full size cargo van with extensive storage designed in to it and there's just me, no pet, no second person! And I'm willing to bet I'll still be scratching my head trying to figure out where everything can go!
When I sewed for a living while on the road, I had a cargo trailer that my supplies could go in as well as all my finished stock and show booth. But then I was making my living doing shows and markets so it was worth it to me.
The other problem is that if you're travelling fairly constantly and sightseeing along the way you end up with precious little time to devote to working on projects. Mapping, planning and living on the road takes up a lot of time that one has available for crafts while living in a home.
I'm not saying it can't be done, just that the logistics of it all need to be carefully thought out both in the planning of the vehicle and while on the road.
As to the market for what you make, you might find an Etsy store more viable than depending on other travelers for a market. We are, by our very nature, minimalists who need little and have limited space. People run Etsy stores quite successfully while on the road. You can load items from anywhere and ship product anywhere there's a post office.