As a Northerner who moved to the deep South, I can answer that. Everyone we met when we moved was gracious and kind. There was never any hostility at all. They went out of their way to help us, and to make us feel at home. One of my dearest friends is a native southerner, whom I keep in touch with even though I now live in N. Mn.
There was never any anti Catholic sentiments at all. However, there were very few Catholic churches. For example, there was one in our town, and some counties didn't have any! The main churches were, Church of Christ, Baptist, and Methodist in that order. Our next town from us didn't have a Catholic Church.
I think those ideas that you are asking about are outdated and not an issue, at least to us. We felt completely at home and accepted.
