Yes, Nian Gao freezes well. Cut into wedges to easily defrost the cake by individual portions. Otherwise, freeze the entire cake as is. Either way, tightly wrap in plastic film and place in an air-tight container.
To defrost, keep the cake at room temperature until soft and stretchy.
Or, pan-fry the frozen Nian Gao directly. Use a non-stick skillet and a little oil. The outside will be crispy and the inside will become stretchy and soft once again.