195-200 yards. I think their rush defense is pretty good. Looking at the top rushers they faced, they held most of them in check.
John Clay for Wisconsin averaged 5.3 yds per carry for the year, but 4.7 against NW.
Evan Royster for Penn State averaged 5.9 yds per carry for the year. Against NW, if you take out his one longest run, his other 14 carries averaged only 3.5 yds.
Ralph Bolden of Purdue averaged 4.7 yds per carry on the year. He averaged 2.9 against NW.
Auburn averaged 5 yards per carry on the year and 42 carries per game. Even if NW holds Auburn to 4.5 yds per carry, it would still put us at 190 yards.