Hello Marie. I'm familiar with the White Plains and Poughkeepsie areas. They are about an hour and a half apart and are very different cities. Poughkeepsie is more rural while White Plains which is closer to NYC is more urban.

Poughkeepsie is also home to Vassar College so its a very college town with bars and such. I wouldn't recommend it for a family reunion. There are seasonal events that go on there, but not sure when your reunion will be taking place.

White Plains is also a college town (Pace University), but again more urban and with that comes the high costs of hotels. One plus is that there is a nice sized airport in the city which will make transportation to and from a hotel very convenient.

I would contact the chamber of commerce for each city.

http://www.westchesterny.org/ (White Plains, NY)'

http://www.dutchesscountyregionalchamber.org/ (Poughkeepsie, NY)