If you intend to stay in the Manhattan, you'll be hard pressed to find any hotel pools at all. They probably exist somewhere, but I don't know where and they will certainly be in fairly expensive hotels. I'm not sure it's terribly realistic to find one, space is at a premium in Manhattan and most hotels aren't going to give up rooms that bring in revenue for a pool that mostly costs a lot of money.

You might find some outside of Manhattan, in New Jersey if you're willing to take a bus or train in to Manhattan. We stay outside the city all the time and usually go in on the train. It's a little cheaper that way, we usually stay in the Lyndhurst area.

Good luck,

dcman2