How would I handle it? I would write a letter to Marriott customer service complimenting the way this location is handling an obviously-difficult situation! While it's certainly an inconvenience to have the A/C out, "stuff happens" and it sounds like the hotel is doing the best it can. Having done some construction work in Hawaii, I can vouch that contractors there work at aloha speed, which may also be a factor.

If it really bothers you, I would suggest going to the front desk to ask to speak to a manager. Know in advance what compensation you think is appropriate--one night's worth of points refunded to your account, for example. Politely explain why you think that is appropriate and see what they say.