Wisconsin does have same day registration.
However(1), in order to achieve even 60% turnout, there would have to be 5,481,281 registered voters. That would be up from the 3,684,726 number stated on the webpage.
However(2), the 3,684,726 number stated on the webpage may just be wrong.
However(3), the same site shows voter registrations as of 11-1-2020: https://elections.wi.gov/sites/elections.wi.gov/files/2020-11/RegisteredVotersByCounty_11-01-2020.xlsx