You can avoid the mountain grades by heading west and then south. I don't know where you are in NY, but you can come down through Ohio on I-71, and Kentucky on I-65, with almost no grades.
There are some long grades on I-81 & I-75, but by no means what I would call steep. Get in the right lane, shift down, and don't push it. Come down in the same gear you went up, and you will be fine, if you decided to take that route. Just don't let your tranny be jumping around and shift down for some speed control as needed.