With a midnight arrival and 7Am departure I've caught some Zzzzz in the T3 lounge in back. Staff will give you a blanket and pillow if you like. There are some benches that aren't bad but it's not a great option and I'd recommend, for the amount of time you have, to go to the transit hotel if you don't want to leave the airport.

The other option is hit the lounge and drink all night.