Make the reservation for the night, then call the night before.
I stayed at the Hilton in some midwest town, can't remember which one right now. I had a red-eye and really wanted a shower before my day of meetings. I made the reservation for that night, then called the day before and simply asked if I would be able to get my room early enough to shower before 10:00am. They said they couldn't guarantee it, but that it looked like it would work.
I called again when I got to the airport, and when I arrived at the hotel via the only taxi in town, they knew exactly who I was, and had my room ready.
I was HH Gold at the time.
I have done similar things with early arrival and late departure at Hilton properties and for me, as long as I ask well in advance, and then remind them close-in, there have never been issues.