I spent 3 wonderful years living in Watertown NY.
I recommend hitting some of the small towns on the Lake Ontario / Saint Lawrence River shore in addition to Lake Placid.
Clayton has a wooden boat museum that is incredible:
https://www.abm.org/
The original Thousand Island Dressing is from Clayton as well:
Thousand Island Dressing – Buy the ‘Original’ Salad Dressing, originated in the 1000 Islands, in Clayton, New York in the early 1900s. – Purchase the Original Thousand Island Salad Dressing
Nice boat tour of part of the Thousand Islands:
https://claytonislandtours.com/
Boldt Castle is in the Thousand Islands
You can also take a very small ferry to Wolfe Island then on to Kingston Ontario from Cape Vincent. The ferry holds about 7 cars and will make you behind pucker but it is cool.
https://visit1000islands.com/listing/hornes-ferry-to-canada-usa/
