Lisbon airport security closed 00-04 AM but flight leaves at 5 AM -- how can this possibly work?

It will work because there are few people and almost no lines at that time of day. Just be there at 0355. Sleep on the plane.

If it wasn't possible, there probably wouldn't be any flights leaving that early.

Thanks, I keep hearing about how long it takes to go through security, etc, now that people are traveling in droves, and typically places are short on personnel.