Usually I would always say "there's at least a few," but there are just so few Biden voters in Mingo to begin with. And, needless to say, it's seen an absolutely gargantuan swing to the right since 1996. Add to that the fact that it's got a lower life expectancy, so probably a good number of those who voted in 1996 (a higher proportion in Mingo County than the country as a whole, at least), weren't alive by 2020.
I don't know. It's obviously always possible there's that one such voter, but in this kind of case, you can't rule out the possibility that there really is no such voter.