Hotels in both Asia and Europe are quite used to early-morning arrivals. If the hotel wasn’t full the night before, there’s a nonzero.chance that they’d have a room for you as early as your arrival time. If not, you can certainly get them to hold your luggage while you venture back out / stagger around and try to stay upright.

There are luggage storage services at Jewel — attached to T1 — if you’d prefer to wander the shopping center instead, although not much is open at that time of the morning.