People tour for months at a time with what they can pack on a bicycle. I've done motorcycle touring/camping a few times, but only out on the road a week each time. If I was thinking of living off either for an extended period, for sure I'd get a trailer.
There's motorcycle trailers, like Bob's friend, and for whom he posted a couple of guest blogs, which double as sleeping area. The Harley/teardrop trailer setup was way cool, practical, and doable. But note that she had to buy a bike big enough to tow the trailer -- many bikes would be too small. For this kind of thing, on a budget, I'd probably be looking for something like an 80s Honda Goldwing or Kawasaki Concours. Bike + trailer, less gear, setup would start somewhere in the $3-4k neighborhood.
Quality used bicycles can be cheap, but the type of trailer you want would probably be more expensive and you won't find them used much of the time. Cargo bikes have become popular and would be another option. If I was going this route, I'd be looking at a tadpole style recumbent trike coupled with one of the relatively new Surly trailers. And either a coroplast structure on the trailer or a hexaurt flat fold setup which would be way easy to assemble at end of any given day. Or just a tent. With a used bike and a kid carrier trailer, you could probably start around $500 or even less, but for the setup I describe, you'd be at $2-3k. Middle ground would be a decent used bike and used BOB trailer, around $1k