Dear future hubster,
if I am still in New York when you decide to pop the question, I think I can make some concessions about the location.
The High Line falls within the acceptable category, so does the Brooklyn Bridge (direction Manhattan preferred), and frankly, most waterfront spots could qualify in the right lighting conditions.
If you have a slight feeling that this may be a tad bit cliché, you are not wrong, my dear future hubster. It is going to be cliché, a clumsy commonplace. Except that it will be happening to you and me, and we are totally unique snowflakes, and so will be our clumsy commonplace proposal.
We can still proceed to the shoe store after.