If California olives are anything like muscadines, my favorite kind of grapes from Florida, you’re probably right. I have lived in Lexington, KY for three years, and only once did I ever find muscadines (the local Whole Foods had some last September). In other stores the folks didn’t even know what I was talking about. When I did a Google search, I found that according to some Civil War diaries, muscadines used to grow wild here. I guess it means that in the mid-19th century, Kentucky had a warmer climate than it does today.
You mentioned Amish cheeses; I do know of an Amish store here, near Henry Clay’s house. Maybe it’s time to pay them a visit.
They came from my greatgrandmother's farm, and she'd brought them up from relatives in London Kentucky.
There are "other" varietals of yet other species of grape that have been adapted to life in Indiana ~ which is really, really, really tough on grapes ~ except what we called "wild concords", and they also grew on our property. Wild concords taste much different than muscadines in that particular climatological regime.