I remember watching a video for a front-drive hub motor ebike (before the rear-drive became the norm) and they were bragging that with the front hub motor you essentially had all wheel drive. The motor on the front and your pedal-power in the back. And they were bragging on how great this is in the snow. I don't know if it actually is or not, but the idea that it would be has been around before.
It might be interesting to hear from someone with a front hub motor who has used it in the snow. I imagine it would have similar performance results.
On another note. What happens when one wheel or the other slips? Will it spin? Or does it turn off until it has traction again? And how does that affect the motor on the other wheel? In other words: does it have traction control?