Cannondale Cujo 3 semi fatbike 27.5+ , BBSHD width?

Hi forum! My first post here. I have a Cannondale Cujo 3 27.5+ "semi fatbike". The width of the bottom bracket housing is 73 mm. Can anyone guide me wich size Bafang BBSHD I should choose? I believe the chain stays are so wide that I need wider than 73 mm? Would a 100 mm be correct? With some spacers between the motor casing and the frame. I haven't decided where to buy it yet, probably Aliexpress. I'm in Norway, btw. Shipping is expensive, so getting it correct from the start is important. Any tips appreciated.

Hi. Did you find out exactly what to do? I would like to fit the bbshd to a cujo also and have the same problem ordering internationally. Thanks in advance, T