No, and yes. I've camped the past 2 years, (thanks for accomodations, Dick!) and the tent was COLD, and it was hard to find a dry patch. But, it's allowed, by all means...
It's colder than you think it will be in the middle of the night, and you do want to get a good nights sleep, that being said, I do it most of the time when I'm up there, and with a good sleeping bag, it's not too bad. Watch out for Ray's late night parties with Sheppard et al. 0) and don't park next to a guy who has an RX-7 and needs to tune it at 6:30 in the morning.