This, for a 1045 a.m. flight back to U.S.? In Lisbon proper, or closer to airport?
I’d stay in town and enjoy my last evening. The airport isn’t that far, and 7:45, for the recommended 3 hour prior arrival, isn’t violently early.
The Alfama neighborhood.
No need to go out to an airport area hotel. Just not that far from Lisbon proper.
Agree with others. Lisbon metro lines start 6:30am and are reliable and convenient. It took us about 20 minutes (two metros) from Rossio area to the airport and about 10 minutes wait on the security check (to Sevilla) on Oct 7th. The international security line may be a bit longer, but you should be fine to be in airport by 8am.
I would choose to stay in town my last night in Lisbon. As others have said, your flight time isn’t super early, and both metro and Uber are great options for getting you to the airport quickly from an in-city neighborhood (such as Chiado or Alfama) at that time of day.
Thanks for the advice, folks. That's what we'll do.