Do they permit overnight parking? I do not mean for the purpose of staying, but for instance someone is too drunk to drive and chooses to take an uber.

If you ask, they would likely say 'no'. Across the street is a large parking lot. More likely you could stay there and not be bothered. No guarantees, though. It's a small town and police attend to all things thoroughly.

Diversity does not allow overnight parking. You could park on the side street (main street) & should not have an issue unless its marked with restricted hours.

Sorry not really sure. But I don't think so.