The terminal, international or not flight, Precheck, and checking bags or not changes this pretty significantly, especially on your anxiety and experience with dealing with airports.
I’ve left for an airport after boarding before but I have everything status wise and the experience to get through security within 3min 99% of the time.
Personally I’d shoot for 4:45 (no checked bags, Precheck, and know all the terminals) but I’m also not an early riser and probably end up in the 5:20 crew and maybe miss the flight.