Quilting by the Lake is the biggest I know of. There is also a quilt retreat at Wiawaka, on Lake George, www.wiawaka.org.
Log Cabin Fabrics in Ravena has a quilting weekend several times a year at Round Top, in Greene County. Her website is www.logcabinfabrics.net. The info for the web is outdated, but I'm pretty sure there are new weekends planned for 2011.
You might have luck going through a quilt guild. There are a couple of active groups near you, the Wings Falls Quilters, and further down in Rensselaer County the East Side Quilters - I know they just had a retreat.
Good luck, and if you go, have lots of fun.
Janet