Be mindful that if a person looks at the ACA plans in Florida, there aren't any PPOs listed there, either, and yet it's the most popular answer for people who want health insurance with a nationwide network, and works extremely well. There are EPOs that wouldn't be a good fit for a traveling fulltimer, but there are EPOs that are the best fit. So don't get hung up on the PPO designation.
A while back I looked into ACA plans in Missouri and was intrigued by Ambetter. It is offered in 25 states, including Missouri.
www.ambetterhealth.com/health-plans/select-your-state.html
It doesn't have a nationwide network, but it has a network called Bronze | Silver | Gold that looks like it covers all of the areas where it sells policies. For example, I searched using a Missouri Ambetter plan that has the Bronze | Silver | Gold network--I got a bunch of hospitals and doctors in Houston.
If one's travel plans are limited entirely or maybe even mostly to states where Ambetter sells policies, it might be an option, especially if you're healthy. It will cover emergency care wherever you are, as all ACA policies do, and might be workable for routine medical care depending on how often you want/need it and where you travel.
I'll note, however, that Ambetter policies don't have any out-of-network coverage at all. And in the case of an emergency in a place where you don't have network coverage, your care will be covered for the duration of the emergency, but once the emergency is deemed over, any continuing care while in that area will be out-of-network. Of course, out-of-network coverage is never fantastic, because it has a separate deductible and out-of-pocket limit, but I always liked the idea that my insurance company would have a dog in my fight if I were dealing with out-of-network coverage.
