I think it depends on which way you might want to go, and local conditions. You might be able to head in only one direction, if the current will allow only travel downstream. If you are seeking to bug out because the local rivers are flooding, then bugging out via might not be a good option.

I've thought of using the East River to get out of NYC, but it's not really a river. The current in it are strong and tidal. If you jump in at the right time, then you should be able to travel a decent distance on one tide. Currents run at about 3-5 knots (slightly more than 3-5 mph). Figuring that you could make an average of about 2 knots over the period of one flood or ebb tide, that's more than I think most can walk in a single day.

The difficulty in depending on this is know you have the boat and other supplies needed. I simply do not have the room to store any type of a baot that I'd want to trust enough to handle the trip. So, I would consider using any of NYC's river as a route to bug-out only as a last option, and it would only occur with me trying to put something together to float on. It's also not something I can practice.

If you have the space and ability to store a boat, then I'd also hope it was not stored solely for purposes of being prepared to bug out.

Finally, I do not see myself heading for the woods during almost any scenario. I'm a human being not a wildnerness animal. Human beings do better in communities.