Sorry I'm late to the party. But hear hear horror stories of the Luxor's rooms being extremely hot due to the angle of the windows and direct sunlight. I would go NYNY, plus its' just closer to everything as the other responces mentioned.
This is just my theory, but I wouldn't expect the Mirage to be open by October unless COVID-19 takes a nose dive. MGM has been relocating people either to Bellagio or MGM Grand if they have reservation at the Mirage.