I was there about 10 years ago and it was busy, but not unreasonably so.
I could see the wisdom of spreading the crowds out though. It’s a big place.
I assume the other park referenced must be Zion. I’ve visited both in February, lonely places. Put on a jacket, avoid the crowds and pay half for your hotel rooms.
I was there in 1984, and it was fairly empty. Only one National Park camping was full in May, and that was Capitol Reef NP.
Was it only 12 spaces?
Visit “National Monuments” instead—they’re every bit an equal treat!