I just built a BBSHD fat tire bike with a Nuvinci N171 CVT Hub. 350% gear range. I’m running 42T front and 24T rear cog right now. Single speed chain. I initially had some skipping issues with the rear cog. But that has calmed down after 40 miles of riding. I believe the skipping was due to me deforming some teeth on the cog trying to remove it with a brass punch because I didn’t have the Nuvinci freewheel remover tool. I have a new 22T cog being delivered tomorrow. As for handling high amounts of power it is the only IGH hub that can handle up to 2500 watts and probably more of mid drive power. I’m running the stock controller, so it’s showing 1400 watts on my display when I use the thumb throttle. No issues it runs great. With that low gearing it goes 28mph.
The newer version of that hub, the Heavy Duty CVT Hub (aka the cargo hub) by Enviolo (previously named Nuvinci) should be able to handle your motor (110Nm torque), as long as the total weight of you and the bike is not much more than 350 pounds. They also have an Extreme version that can handle a 550 pound capacity at 100Nm torque.
The newer Enviolo hubs shift easier and are lighter than the early Nuvinci N171 hub. But the 3 pounds extra weight isn’t that big of a deal if it’s for a road bike. If your building an off road single track e-bike then get the newer lighter hub.
David at Eco-Cycles in Nashville, TN. USA still has a few of the new-old-stock Nuvinci N171 hubs in stock. They are $80, plus $20 if you want the 6-bolt disc brake rotor adapter. The hub kit comes with axle hardware and the shifter with its hub interface. Once they sell out the N171 it will be non existent as new. He is selling them on eBay.
As for the newer Enviolo HD and Extreme hubs they are $350 and up, and do not come with axle hardware or shifter parts.
Regarding the shifter interface parts for these 2 hubs, it has to be 40T spline. Unfortunately it’s almost impossible to find the 40 spline hub interfaces in the USA. I had to order the ones I needed from ebike24.com in Germany.
Also be aware that all these Nuvinci/Enviolo CVT IGH hubs are for conventional 135mm dropout width frames, not 197mm fat tire frames. I had to bent the rear triangle of the Fat frame I used from 197mm down to 140mm to get the N171 to work. Also had to get a special single speed freewheel spacer to move the cog out far enough to get a good chain line. The cog just barely clears the seat stay. Also I’m using the highest offset chainring from Luna on the BBSHD, The Eclipse chainring with 24.5mm offset.