My flight arrives in Lima at 23:00 and I am planning to fly directly to Cusco the next morning at 5:40. Is it possible to just stay in the airport overnight or would this be a problem? I figured since I need to be at the airport by 4:30am there is no reason to pay for a taxi and hotel for only 3 or 4 hours of sleep.
No problem at all, the Lima Airport is open 24 hours, so you won't be kick out. There is a food court, ATMs, money exchange places, Internet cabins, etc.
Also, it's not very big so you won't get lost. It's crowded though, so keep an eye on your luggage all time.
Have a safe trip,
Thanks for the information Ivan.
But also be in the counter of the domestic flight 2 hours before !!! no one hour