Bob, you are more time-challenged than even me!
You've never been above 10K? AMS doesn't hit most people until above 12. GET THAT DIAMOX! Hiking to 12k and sleeping a few hours there is not acclimating. It is more like bringing on the AMS symptoms, so when you wake up you feel like cr@p.
With your tight schedule, it may be dark by the time you reach Outpost Camp. Sleep there, get up a little earlier, and save your body the brutality of both hauling a heavy load the extra 1,700' elevation (and back down) and trying to sleep where many get AMS. (There are a few places between Outpost and Trail Camp where you can sleep, if you want to split the difference.)
You didn't say how much time you are spending in Utah at elevation.
I hope you and your partner can take turns driving back to Vegas after the hike!
