WARNING SPOILERS!
So the answer implies that the VW Microbus has too much torque. As a long time VW fan and previous owner, I think “too much torque” and VW Type 1 engines has never been a problem… 
<b.@mrbell321
I Have Not Seen The Puzzler…
…But, A VW Microbus Is A Type 2, Not Type One.
The Earlier Microbus Had A Special Gear-Reduction Rear Axle, Not Found On Type 1s. Standing behind one of the type 2s, one could notice that the axle met the back of the rear wheels well above center and gave it more ground clearance.
Does this help with the puzzle?
CSA
I’d guess the drive tires sliding on snow seems more like it is related to wheel speed than torque. Static vs dynamic coefficient of friction and all.