I'm positive you should be able to order some online
I did some quick searches of random producers on Total Wine just now, and they've definitely got some stuff there.
Never tried Total Wine but depending on where you live they've got natural wines there. It just isn't categorized as such, again «natural wine» is a term that adheres to a philosophy and not a certification. Vague, I know. But it is what it is. Basically all these people are just saying f*** additives and chemicals and yielding 150.000 bottles of predictable product that manipulates the terroir and grapes into something its not, just for the sake of money
These people are not making bank at all, but they make damn good wine. And yes there's definitely a bunch of natural minded producers on Total Wine, if you know what to search for (and what you like)