If you’re doing 81 instead of 87/95, 100% stay on Hwy 401 until you get to the Thousand Islands Bridge (I-81) border crossing.
Route 11 through northern New York is a perfectly nice country highway, but you’re adding time compared to 401 to what’s already a long drive for you. That said, there is almost always some construction on A-20 west, and the 401 is prone to closure by tractor-trailer accidents in the Brockville area. Fortunately detouring on Hwy 2 if that happens is usually decent.
I would agree except that we usually cross at Ogdensburg and cut to the 81. It's 3 minutes longer according to Google Maps but based on my experience, the border crossing is much faster and you avoid some of the risk of accidents on the 401.