Another idea. Have the first part of the convention onboard an Amtrak train picking up attendees. Eventually arriving in New York as a destination, and then continue the sit-down on the return journey. Possibly even reserving a bar-car and a pullman? (now that would be a blast)
Here is the url to the amtrak page that has a link to a route map, and also at the bottom of the page the list of route's and the cities they pass thru.
