Therefore, if you aren't riding it it is best to plan to stay west of 9W on Sunday, unless you like lots of company.
Trying to cross the route can be problematic. Some roads may be closed to cyclists not participating (e.g. Henry Hudson Dr. through the park, maybe others around the GWB in Ft. Lee).
Portions of the route that are ridden after Bear Mountain are usually OK, except for the aforementioned roads in/around Ft. Lee.
Good luck to GFNY riders, the weather looks like it may cooperate.