Champlain is almost 200ft deep where the current ferry crosses to Grand Isle. Apparently the Army Corp of Engineers considered the idea of a suspended tunnel back in the early 80's, but dismissed it due to the lake bottom being too soft and high winds being a concern. It seems like many suspended floating tunnels have been proposed across the world, but none built yet, though China and Norway are actively pursuing the tech. Would be interesting to see VT/NY be the first to use such a tunnel, but I don't see it happening.

https://vtdigger.org/2022/05/08/new-yorkers-with-vermont-ties-push-for-a-new-bridge-across-the-lake/

I do think a suspension or cable-stay bridge could be designed to cross the channel between NY and VT and be aesthetically beautiful