I will say this.. The board will not let you ride if its motor, battery and controller are 32F or below. I proved this yesterday after receiving it back from FM for a repair. I tried to fire it up right out of the box after being on a FedEx truck in single digit temps all day and it gave me a 16 error code. I let it warm up to about 45 or so and it was operational again.
Interesting... I haven't let mine get that cold but I guess that's a good failsafe.
I haven't had any issues with cold so far, but I always take the board inside immediately after use so nothing has a chance to freeze. If you take a warm board and freeze it, you'll get water condensing inside your battery and control modules because the warm, relatively humid air can't escape fast enough through the little vents. Take an empty water bottle and freeze it, and you'll see it fogs up on the inside. Is this a huge amount of water? No, but I can see why FM doesn't want to risk it. That said, I'm not sure how they could prove it was freezing temperatures that caused the damage. Ride your board a little outside in the cold and check the temp gauges in the app. If your board is like mine, your components will all be reading way above freezing.
I'll definitely keep an eye on the running temps in the app... as soon the snow and slush is gone... which at this point seems like it'll be mid March...