Hoping someone can assist me with a question that I have on an upcoming reservation out of DEN. I am Gold (through Amex Plat), if that matters.

Rental details:
Pick Up: DEN Sun., June 5 @ 11am
Return: DEN Wed., June 8 @ 7am
Mustang GT / Camaro SS (V4)

I now have to fly out of DEN on June 8th on a 6am flight and will be staying at a hotel near the airport the night before (6/7). I am not able to update the reservation to return the night before as it says the car I selected is not available if I make these modifications. Also, not able to re-book the reservation to return the night earlier either, as this car class is not available (and I would really like to keep the car I selected for some Colorado mountain driving...)

So, I think I have two options. Does any one have any recommendations?

1. Return the car around 4am on Wednesday, June 8th. I assume I can just drop the car off at this point even if they are not officially open yet? If so, is the shuttle to the airport terminal running at this time? Hopefully no early return penalty would apply by returning it 3 hours early?
2. Return the car the night before it is scheduled to be returned (Tues., 6/7) around 10pm, and take the hotel shuttle or Uber to the hotel that night, and hotel shuttle or Uber back to the airport terminal the next morning. I am worried that I may be penalized for early return if I go this route since I am not set to return until the next morning -- would I get charged a higher rate / penalty if I did that?

Any suggestions appreciated! Thanks in advance.