leave Friday and drive to Vegas, then drive the rest of the way on Saturday morning.
Now I'm realizing the unfortunate circumstance that Utah and USC will be playing in Vegas on Friday night, meaning increased traffic from Salt Lake to Vegas on Friday, and possibly increased traffic from Vegas to SoCal on Saturday (though I'm hopeful most USC fans make a whole weekend of things and stay until Sunday).
Add to it the likelihood of stormy weather in the early weekend and it may be an "experience" driving down there. I will admit, though, I'm tempted to deck my family out in all BYU gear when we are in Vegas during the game.