Originally Posted by
lsquare
Not really. Recently I had a 4 AM flight out of BKK and I just hung out in the city until midnight and then headed to the airport. If I have an early morning 6 AM flight out of LHR, I will avoid paying for a room unless I have to.
You never "have to" pay for a room but in the OP's case they arrive at 18:50 and leaving at 09:30. That's a long time to be wandering around an airport and maybe getting some sleep on a bench.