Single night stay or multiple night stays? Other than the power outage which is probably municipal issues, did you try to change rooms?

for kicks, if the hotel never responded with a refund, what were you going to do then? At this point Marriott appears in trying to take some responsibility with the offer of 30k (although after some other low ball offers per your accounts). I would just take it and call it a day.

as you are a 7 year platinum, I can guarantee you won’t be leaving Marriott anytime soon . Just write this specific property off (and maybe even identify the property so others can avoid).