For work reasons, I'm trying to leave my hometown as late as possible WITHOUT ACTUALLY MISSING THE FLIGHT, lol. What's the minimum reposition time you'd leave for Dulles?

Coming into C or D (UA), departing almost certainly from A (AF). AF is J, so no real need to board the second it starts as long as we make it before doors close. No checked bags. Okay with a bit of hustling.

Am the type to show up to airport 1hr before flight (w/ precheck), so pretty chill with tight connections. What's in the realm of safe vs stupid? Yes I know .... can happen any time, it's just a long time since have connected through Dulles.

Thanks!