Both Gil;ead & Gleneida are deep lakes with Trout & Lakers in them, but, they don't freeze up every year. Same deal with the reservoirs....very deep, last to freeze. I've heard of some smaller ponds in the Peekskill area but haven''t fished them myself.
A little bit North you will find Sylvan Lake (near Hopewell Jct.).....also deep water, but productive fishing.
There's a bait shop near Somers, NY ...Bob's Bait at intersection of Route 100 & Route 35.... great people there (see John or Lucy) with reliable information.
Good Luck.