This is by far the most common question that we get asked. The answer is fairly simple. Both of us borderline enjoy going in the woods. Some of my fondest BM’s have been while perched on a downed tree or on a hillside outhouse.
If a cat-hole isn’t available, there are public restrooms in almost every town that we have ever travelled to and they get cleaner the further you get from the South.
-EDIT-After a year of full-time travel and plans to branch out into the Eastern US, we caved and built a toilet into our bus. We use a cassette toilet that has to be dumped every 1-2 weeks like a black tank, but requires zero plumbing.