We did a 1700 mile trip from the west coast of Florida to eastern Connecticut in April-May of 1996. We had a good weather window on the Atlantic side of Florida and went offshore at Ft. Pierce to pick up the Gulf stream. 72 hours later we were in Beaufort, NC. We went inside and up the ICW to Norfolk and then up the Chesapeake to the C&D canal. It was then down the Delaware to the Cape May Canal. From Cape May we headed directly to Montauk Pt and on to eastern CT.
We had a crew of 3 guys, including a first mate with offshore single handing experience, and were properly equipped with life raft, EPIRB, redundant navigation gear (Loran, GPS, sextant) and had a SSB and a 2 meter ham radio. We had predeployed extra running backstays and a babystay and had storm sails at the ready. Thankfully, the weather was great 95% of the time.
Some things to consider: Going offshore--especially if you pick up the Gulf stream--will save you a lot of time by avoiding the ICW meander in the far south and lots of drawbridges. We probably saved 2 weeks by taking the 600 mile offshore route to NC. However, to stay in the Gulf stream, we were 140 miles offshore as we passed Georgia, so we had to be prepared to stay out for a while. We went in at Beaufort, which is one of only about a half dozen Atlantic coast inlets that you can use in bad weather. We had ducked in as a front moved in from the north, with 30 kt winds. Going around Cape Hatteras was out of the question, so we entered the ICW at that point.
If you followed our itinerary, it would take you at least 2 weeks to get to NY, but you would need the weather gods on your side. If you stay in the ICW the whole way, you would probably need at least another 2 weeks.
If you have the time and are willing to wait for the right weather, go for it!