The Montreal to Sherbrooke route
Highway 10 east from Brossard toward Magog then Sherbrooke. A natural stop in Magog or Bromont breaks up the drive and gives you photos.
Once there, Route 108 toward North Hatley and Lake Massawippi is the most rewarding loop: curves, water views, light weekday traffic.
Return on the same Highway 10, or via Route 112 if you want to stretch it. Budget the mileage accordingly.