PS. maybe this is a bit more helpful....
there's a 'cross series in Verona NJ. check out montclairbikery.com. i guess you could take the train from NYC out to montclair and then bike 15-20 minutes to the course. that series runs through Oct. in November, another series starts in Sussex County NJ.
The Highland Park Cyclocross race is November 6th (UCI Cat 1) and completely accessible from NYC by train....
Take the train into New Brunswick and the course is a 7 minute ride from the station.
http://www.midatlanticcross.info/2005.htm
Take a look at last weekend's UCI races on Long Island, and you'll get a good sense of what NYC clubs and teams are travelling to races.
Day one:
http://www.bikereg.com/News/Results...Southampton.asp
Day Two:
http://www.bikereg.com/News/Results...Southampton.asp