As for building height, the highest buildings I've seen around 125th st. (where you end up if you extend the centerline of 31) are on the order of 21 stories. So I'd liberally put building height at 300 feet ASL.
Could he have made it? Maybe -- I'll wait for the reports from the simulator on that one. But they'd have to have been luckier than they were.
Let's be honest here: it'd have to be a spectacular screwup such that in those final feet of low-power flight, the aircraft caused anywhere near the casualties on the ground than people it had on board.
The "worst case" on ditching in the Hudson *might* be 155 dead, but that would require a spectacular screwup as well. On the other hand, the odds of the majority of passengers surviving a controlled-flight water landing are pretty good, while the same numbers for an urban landing are not so great. So "worst case" for a ditch is a significant number of survivors.
You can argue out the details: was flying over water and attempting a relight a good idea, or should they have just kept it where it was, since it was working to some degree, and tried to put it on a runway, hoping that the situation didn't get worse?
But, what it boils down to is this: there's the moment to make a decision. That decision's not always the best one, but it is best to make it. And there's the moment to realize that the planned course of action isn't going to work out. That moment is way before it starts to fail: ideally, it's when you catch the first whiff of cognitive dissonance. When the odds look good, but the number of unknown and uncontrolled critical variables starts to increase, that's when it's time to simplify. You can only get so lucky.
And these guys couldn't have gotten luckier.