Okay, to (hopefully) end the discussion once and for all, I asked Nathan Greno directly about where Corona is supposed to be.
Now, granted, he said the very interesting thing about not thinking about it as Corona, since they chose not to call it that in the movie, but… it’s the only name the kingdom’s ever had, and since they call it that in the series, what else are we going to call it?
But, even so, my point is that it is not Germany. It’s just a unique but generic fairytale kingdom that draws inspiration from several sources.
“maybe the witch thought she was protecting rapunzel, not punishing her. maybe she thought that if rapunzel was locked away, no one could ever hurt her. maybe the witch kept rapunzel because she loved her, because she was scared that if other people could get to rapunzel, they would hurt her. and maybe rapunzel didn’t understand the witch; maybe she was angry at her - but maybe she loved her too.”