I am considering taking a trip from BDA to LAS with a friend who is, let's say, not small in stature. I'm gold, he has no status. The trip will presumably be BDA-PHL-LAS. I'd like to get upgraded of course, but it's not as big a deal for me, I can survive a long flight in an exit row, he might not be so comfortable.

What's the best strategy? I sense the mileage upgrades come from the same bucket as the automatic upgrades? So if we got to the gold window and didn't get upgraded, it would not be possible to buy up? Obviously I'd like to put him on my PNR to avoid the fee and pay just the miles, but can you do a mileage upgrade on just one ticket on a reservation? And what is the mileage price? The "Carribean" price is 15K, does that cover the trip from BDA to LAS? BDA-PHL is not that long a flight, a right around 2 hours, maybe doable in coach for him.