Depending how you get access, there is another lounge called The Club at LAS which is fairly close to Centurion. If you have an Amex Plat card, you get Priority Pass which will get you into The Club.
I never get to the LAS club before 8-9PM. It can be kinda croweded at that hour but it clears out as people leave for their flights. It closes at 11, which is my usual flight time.