Best selection in NYC is at Tents & Trails and it's year round. They don't have everything but you'll see the Koflachs, some scarpas and the Vasque plastic non double boots. Their staff tends to be good. They stock sorels as well.
Last season paragon had a single model of plastic boot I don't know if they'll have them yet, their staff tends to be pretty poor.
Today at EMS they told they will be stocking plastics but didn't have any in yet. This will be new for the NYC EMS.
So I'd say Tents & Trails, but if you do make it out to Campmor, check Ramseys Outdoor just down the road they may have a better selection.
And don't dismiss the Columbia and Vasque insulated hiking boots rated in the low negatives. There were a fair amount of them at last years winter Gathering and no one was complaining.