We might have to drive through Toronto on the way back; but we can take more time then.
The planned route is going to require three 11-hour driving days; but we can make it with time to spare. The last day will only be six hours so we can rest up for the actual reunion.
Mostly, I am trying to ensure we have reasonably-sized towns to stay in so we have a choice of motels/hotels. I don't want to get stuck in the middle of nowhere (i.e. between Sault-Ste-Marie and Thunder Bay) when we are too sleepy to drive.
I haven't plotted the drive home, and might just leave it unplotted. Maybe we'll just follow the Trans-Canada Highway back because timing won't be as crucial as on the trip there.