Re: 1 free day in NewYork, where to fish?
Causeway said the truck hit Eastern Nassau and Western Suffolk. Didn't see them in Hempstead today but did have fun playing with the pickerels. Some sort of hatch was going on too, did hear the dog walkers complain about having to walk around with their mouths shut. The NYS DEC posts a list of lakes on the Island that are stocked, and gives some very good intel on how to fish them.
If you consider CT, just remember you need to get a license and there's only a very few spots that are open this time of year. And they do enforce. There was a very good shop in Darien (Complete Angler?) who can get you some great info and get you a license. I'm not familar with the Merry Brook(?), but I do have a faint memory of the Mianus River being one of the few exceptions which would be legal for this time of year, which is before Stamford, but I'd check with a shop in CT.
I'd also advise staying on the Island, as the trip up the turnpike or the Hutch is both $$ and frought with delays. Borrow someone's EZ Pass just for time time savings if you do go. Look for one of the lakes mentioned earlier or in the DEC page. If you don't get trout, you'll probably get something else. Good luck!