After the inaugural tour on the Moonlander, tire pressure is king for fat bikes. I wouldn't have thought that the difference between 8 psi and 6 psi would be so pronounced but it is. Going uphill to Brooks Lake Lodge was a fucking grunt and we averaged perhaps 4 miles an hour (5.2 miles took us an hour and a half to ride with stops). Even with 4.7" tires I still would bog down in spots and had trouble getting going again. Snow really slows you down on the trail, and we spent a lot of time moving from one side of the trail to the other to find a firmer surface. You would easily bog down and stop in places where snowmobiles had just ridden (too soft a surface). Because of the drag of the snow, it took a bit of effort and coordination to get going again after stopping, especially on a hill. After nearly having a heart attack, I let a few pounds of pressure out of the tires and eureka, I could ride much easier. Going downhill was also sporty (the fastest we got going was perhaps 12 mph; a fucking rocket ride on a fat bike.)