You say its overpopulated, I see a state of mainly suburban small towns at least outside resort developments when I visited the place. There’s no shortage of space to meet demand if one builds up like is done in Japan or Hong Kong.
If Hawaii were overpopulated, we would see people leaving for other areas because there are too many people. Instead we only see people leaving because it's too expensive.
Agreed that housing on vacant land isn't the answer. The answer is to build up, in more socially-orinted ways.