I travel pretty frequently for work and it seems like it's always an early flight. My advice, sked a cab! They're cheaper, they don't cancel at the last minute, and you can use an app to track them, pay in advance, etc... I've used yellow cab - no complaints.

My last 6AM flight, I sked an Uber the night before, and at 5:15AM, Uber had an issue and it was a fucking mess to get to DCA on time.