With your scheduled 04:10 arrival I'll guess that you are arriving from South America. Your profile indicates you are an EXP, therefore if your onward flight at 20:30 is on a oneworld carrier you will have access to the Flagship Lounge. It's generally very quiet for most of the day, has showers, food & beverage, and comfortable lounge chairs that are sleep inducing. That's where I would go .
Good guess! Just in from Carnival in Rio/salvador, being EXP it seems I will hit the flagshiplounge.
Hotwire has airport rooms from 62$. Might do that, and then head down to South Beach for dinner.
Thank you all.