We did that trip enough times too that I saw the good, the bad and the ugly. Helped me to understand the difference between "buying" a boat and "owning" a boat as an adult.
I remember one stay at the same harbor in a different boat and having engine trouble. Boat was a 1957 39' Richardson (all teak and mahogany and absolutely stunning) w/twin flat heads
One motor needed either and alternator or starter and someone in Goderich figured out it was the same thing used on a Massey Ferguson tractor The old man paid a guy to drive from Goderich Ontario to Detroit to pick one up.
He and the other gentleman that used to cruise w/us were both very good at dealing w/those issues when they came up which is key in a trip like that.
Pretty sure their Martinis became much stronger