As another born and raised Wisconsinite:

There’s the superficial “friendly and welcoming” that applies to everybody. You’ll wave at everyone you see and lend a hand if their car is stuck in a snowbank.

But there’s also a very insular clannishness where you will never get beyond a surface level unless you’re “one of them”.

However this is less of a “Wisconsin thing” and more of an “every northern rural area” thing