I've found Mapquest to be less than accurate at times. Google maps is pretty spon on up here, and has the difference between Rockland and Belfast at 30 minutes.

It's really a matter of timing. Craig indicated the drive back up would be on a Wednesday, so whatever traffic delays he might experience on Route 1 through Wiscasset should be minimal compared to the weekend. And depending on what time he goes through, it will probably be a non-issue altogether.