Last week a poll was posted that showed the expectations for wins in the remaining games. (Insert credit here to the OP). That polled showed the chances victories as follows:
Those expecations may have changed after the Illini win, but seems like they would probably still be approximately accurate. Based on those expectations.
Average expected regular season wins: 7.15
Regular Season Wins Chance
The overall chance of getting to 7-5 or better is 91%, but the chances of reaching that without a Purdue victory is only about 3% (pretty obvious).