I've done all of that route, in fact did the 75 miles from Brewster down the N/S County trails, into Manhattan, down the West Side, and across the Brooklyn Bridge. My normal commute though is from Brooklyn into Manhattan, 10 miles each way. Some days I wear street clothes, but mostly I wear my road cycling clothes on my old Trek MTB/Commuter. I'm going to be sweaty after 10 miles no matter what the weather, so I have to change anyway.