How far in advance would it be sensible to leave the Premier Inn at the airport for an 06:10 departure (HBO)?

Been through NCL a few times already but not familiar with what the fast track queues are like at that time in the morning. Would 05:20 be cutting it too fine? Don't care about the lounge or group 0, I'll get fed onboard!

Slightly annoying there isn't a slightly later flight, the next one is 09:35 which is too late for me really.