Sanders obviously would have done much better in the upper midwest and we don't know if a 2020 Democratic nominee will be from this wing of the party yet. Guessing it will be a left leaning Bernie type though.
That would've been my assumption too, except Russ Feingold lost WI by an even larger margin than Clinton. Feingold is a Bernie type Democrat. I'm not convinced that they would've embraced Bernie any more than they did Hillary, except maybe due to the perception that he's more sincere trustworthy. I think it's entirely possible that personality plays a much bigger role than policies. How else do we explain states voting for two vastly different politicians 4 years apart?