So here's my recent experience with cold temperatures in an EV. Unfortunately not with my Zero, as the roads are WAY too icy and snowpacked to take it out. Last month I received my Tesla Model S, and it is sweet. It arrived in the middle of a cold snap, and in Manitoba that means COLD. The lowest temperatures I drove it in were -32*C with a (standing) windchill of -43*. Everything worked well, even after standing outside for several hours in an exposed parking lot. The car will turn off regen braking if it is too cold, because it can't charge up the battery below freezing, but discharge is fine. I've had no trouble with electronics. Range obviously decreases, although part of it is because the Tesla has a thermal management system that heats up the battery pack (so that it can be recharged, and regen kicks back on after driving for about 10 minutes in -30*).
I'm GUESSING that in extreme conditions the Zero should drive alright, with seriously reduced range, but don't expect to charge outside a garage. I just don't have the gear right now to drive in our crazy cold (I need to borrow my dad's snowmobile helmet & suit, and get some serious winter tires on, maybe chains). Maybe next winter! Do we know if Zero has done any cold-weather testing (and not just Californian cold)?