Update: rode Lewis Morris on Monday 2/15. I ride a Trek Fuel Ex with 3" mid-fat tires. It was extremely difficult. Some fun fast descents in a foot and a half of pack (god forbid your front tire goes even a tiny bit off the packed stuff or have fun going OTB, like I did probably two dozen times). Saw one other guy on a bike, it was a fat bike - I'm sure he had a great time. I sure didn't!
Overall I give that ride 1 bag of popcorn and a little bronze statuette of a fat bike tire, because that's what I should have been riding.