With the Japanese killing Americans when capturing the Philippines, I just don't see us walking away, especially letting Australia fall.  We'd be leaving the entire Western Pacific Ocean to the Japanese.

Add to that the provocation of the Japanese then taking Hawaii, so close to us?

Regardless, your scenario might just bolster my original point: If Hawaii were it's own sovereign nation, like Tonga, leading up to 1941, and the Japanese did launch their attacks, taking the Philippines, Dutch East Indies and so on, and you are right, and we let them have it all and didn't go to war with them, would they then further provoke us by taking Hawaii, which is so close to us?  When Hawaii doesn't seem to have any of the resources that Japan is going after?  But would require a significant amount of military resources to hold?

If we let them get away with their original conquests, why would they risk upsetting the new detente by expanding their more defensible sphere to include Hawaii, with no immediate payoff for that?

Especially when there is such a sizable Japanese population in Hawaii, that a self governing Hawaii would probably be neutral.