Here’s a suggestion:

Make a safety hotel reservation for your week.

Sign up for Redweek.com and prowl it compulsively for last minute deals that typically come up when a timeshare owner cancels a trip. Keep prowling until your hotel is non-cancellable. Do some pre-planning regarding parts of Maui you will/won’t accept so that you can strike quickly.

You will also then have a kitchen, which should save you some money, and many/most timeshares have no parking fees. VRBO will give you a sense of pricing and you might see something there that is likable.