Driving, and looks like there are 3 choices. Are any of these routes "mountainous", do any include "high" bridges or overpasses ("high" meaning many feet above the water? I've got a thing about heights.
I see that 2 is somewhat recommended over 89. And that a ferry or boat ride on the Champlain is a highly recommended thing to do, so taking the Port Kent Ferry would get us there and include a lake ride (all in one).