It's great that you have such a garden in the city! I well remember visits to my grandparents at 1000 Hudson Street in Hoboken, shopping in the little stores on Washington Street - Ken the butcher (sawdust on the floor), Arak's Deli, Hans Jesse the baker, and the greengrocer down on the corner ... they all had free samples for me ... a jitney ride up to the A&P for staples like flour, sugar and coffee. The ever-present aroma of coffee brewing at the Maxwell House plant, and falling asleep to the mellow sounds of boat and fog horns on the Hudson. OK ... returning from memory lane...

According to Burpee, this perennial plant is winter hardyin zones 4-9.

According to the director of Rutgers Gardens (in a class I took on winter containers), you can safely overwinter a plant in a container if it is winter hardy at least 2 zones colder than the one you are in.

Assuming you in Hoboken are no colder than zone 6, the plant should be safe overwintered outside. Since it is hardy as far south as zone 9, it probably doesn't need a freezing dormant period either, so probably could overwinter in a cool protected location like garage or basement.

Our winters in NJ are crazy, and the repeated freeze-thaw cycles are very hard on container plants. Since they're above-ground the warming effect of the sun and chilling effect of wind are more pronounced than on plants growing in the more stable temperatures of the ground. Therefore, a little insulation of some sort around the pot wouldn't hurt. In my garden, I would sink the pot into the soil of my empty vegetable garden (maybe not an option for you) or pile some shredded leaves around the pot. I think that will give you some ideas. Whatever you do, make sure the plant still has adequate drainage.