In that case I'd take advantage of Twilight Check-in the night before (don't try eariler than that) where you can check bags in and get boarding passes for the next day. This is after 16:00 hrs, but in a way it's best after about 18:00 hrs since passenger throughput drops like a stone around then and so there shouldn't be much queuing and the agent will be able to give you all the time needed to make the experience good for you.