There are a bunch of races that allow mini's to enter. The closest to you is the Greenport Ocean Race. Out of Newport you have the Bermuda 1-2, Solo Twin and the Ida Lewis distance Race. The Annapolis Race has let Mini's race as well. There are more races the further south you go. Basically, almost every major US race will allow mini's as long as we can get enough boats for a class.
Feel free to contact me directly for more information. I am located at the east end of Long Island.