I live in a dense part of NJ, around 7000 inh/mi2. But I've got a single family home with a nice yard, and many of my neighbors have even more space than I do. We've got lots of trees and open spaces too. At this density we'd need 5 New Hampshires, but that's still not much and it would provide a much higher quality of life than packing in at 35000 inh/mi2.