According to the National Weather Service a "dangerously cold" arctic air mass is expected to move into the region on Sunday night, just as the game is ending. From the NWS:
***Dangerously Cold Air Expected Sunday Night through Tuesday***"An intense arctic air mass will move into the Great Lakes region Sunday night and remain over Wisconsin through Tuesday. This air mass has the potential to produce the coldest temperatures across northeast Wisconsin since February 1996. Bitterly cold wind chill readings of 30 to 50 below zero will be widespread across the region. Low temperatures may fall to 30 below over north-central portions of Wisconsin and to 20 below over the Fox Valley Monday and Tuesday morning. If you plan on being outside, be sure to dress warm using layered clothing if possible, as frost bite can occur in as little as 10 minutes in these conditions."