No idea as to how long you would have been at HNL prior to your departure. However, personally, if I have a midnight flight, I would splurge and pay for an extra night at the hotel. Yes it is pricey, but you will be surprised at how much it feels that you have an extended vactaion; i.e. an whole extra day.

It also depends on the reception staff. Checking out "early" at 8:30 pm at the Renaissance at Time Square, NYC last month (when we did book for an extra night), the receptionist only charge us $100 for the last day instead of the full price of $500+ because the cost of the room had not been automatically added to the bill as yet. We did not ask for this arrangement but were offered it. We have no status with Marriott so it was the reception staff being nice.

If you do not want to take a chance of being charged for the full night's rate, then an option is to wait for the morning of the check-out day to see if they are willing to let you have a room for half a day (say until 6 pm) for a small fee Hotels may do this if the room would be empty anyway and if their housekeeping staff who would turn the room around in the evening when they are providing a turn down service. A place like HNL where flights come in at all times of day, particularly evening flights, have a better probability of such a practice. However, this does not really work in Las Vegas where hotels are more concerned with their casino business rather than their hotel business!

Some hotel chains charge by 24 hour occupancy; i.e. if you check in late evening, you get to check out late evenings. This is works at the Sofitel chain (not sure if they have a hotel in HNL) and one or two others.

I do not think there is anyway to have a nice leisurely dinner at HNL or around HNL.