I make the reverse of that commute daily, and have been for 7 years.
I go from downtown (north side at Irving Park/California) and back. Takes me 45 minutes flat in the morning - I leave at 6am. Coming back in, if I leave any later than 3:30, it's an hour and a half minimum. That is typically the case going in both directions in peak hours. Luckily, I have the flexibility in my job that I can commute "off peak" hours.
So a lot of this depends on what time he's on the road. But if he's going to be travelling during normal rush (6:30-8:30), he's going to be in traffic for 1-1.5 hrs in each direction everyday.
But no, Deerfield, Winnetka, Wilmette won't make a difference. The further east/west from the expressway you get, the longer his commute gets, as well.
Can he take the Metra instead? That a no brainer around here for suburban folks coming into the city each day.