Re: Sailing from New York City to Montreal ... how long?
The navigation will take about 30 seconds, to draw the line on a gas station map.
Actually sailing the boat up--or powering it up--is something else again. IIRC the mean depth in the Richelieu is only 4.5 feet, so for many boats the answer is "ain't gonna happen".
And IIRC Champlain is a no discharge zone, if you've got a head aboard you'd better expect to secure it.
How long does it take to get from here to there? How long is a string? A lot will depend on what kind of boat, more will depend on the time of year. It could be a fun trip, or a good reason to rent a trailer.