FYI - I just rechecked car rental rates for my trip in November and costs were way down - like 1/2 the price of when I booked a month ago.
I had booked through Costco to rent Fri-Mon at the Alamo onsite at Aulani, now I'm able to get the whole trip at a weekly rate from Hertz (my preference) at the airport for <$100 more. Considering we won't need an XL Uber to/from the airport its a much better deal.
Seems like rates have come down, but I suggest checking a few different ways and using corporate or credit card discount codes where you can.