Franken has not resigned.
As a city administrator I’m on a variety of government email distribution lists and Franken’s head staffer for the region just sent out an email indicating that her job is ending and provided personal contact info for those wanting to keep in touch with her. I’d say that’s the most definitive evidence that Franken might actually resign. I won’t fully believe it until I see it myself. The Lt. Governor is every bit as kooky lefty as Franken - but NOBODY I know knows her name or much about her so going into the next election cycle a solid conservative will not have to compete directly with name recognition / celebrity.