How to keep my beautiful Hibiscus safe during the winter on long island?

This past spring my wife and I purchased a beautiful 3 plant twisted Hibiscus about 4 feet tall it has been out in the sun all summer and produced the most beautiful hand sized blooms day in and day out in 33 years at our home we have never seen hummingbirds and now they frequent this plant almost every day we would hate to lose it how can I winter over this beautiful plant. Thank You