Is there any VP pick (apart from M. Obama) which could help Biden / Sanders to win Wisconsin?
I think any of Midwestern female politicians. Tammy Baldwin is Senator from Wisconsin and she is quite popular in the state, I think she would bring progressives to the ticket and help in Wisconsin. Amy Klobuchar, Gretchen Whitmer and Tammy Duckworth would probably also help him winning Midwest, including Wisconsin
But I'm more worried about his chances in Michigan. Many general election polls show that Sanders leads by more percentages than Biden. I would say that Biden needs to take Michigan very seriously in the general election. Arizona is now more likely to flip than Wisconsin. So, Uncle Joe can still win with these results:
Though, I think that Joe is very likely to win North Carolina
I think Whitmer is almost the perfect choice for Biden. She is young, charismatic, from swing state. The bad thing is that she has only served as Governor for 2 years