Good video! The trails seem to be good for snow biking. I planned on going there last Sunday but wasn't sure if they were rideable. I decided to stick riding on Ice Age trail between Milton and Janesville.
There were some spots where I was trying to climb but just couldn't get enough hookup in the back, and of course the front would wash out on some of the tight switchbacks, and of course where I couldn't see the edge of the trail. A lot of it I just chalk up to inexperience on a bike like this. I literally felt like I was completely re-learning how to ride a bike.
I wonder if Muir trails might be better for snow riding since it has slightly less steep hills and tight single track. I have been learning how to ride a fat bike over snow and agree the front wheel would wash out easily where the ground isn't level. But it's fun riding where it was unrideable.