Well, depends on what you mean by that. If you're talking about long-term longevity, cold actually helps: lithium-ion cell capacities generally degrade more slowly in cold temperatures.

I own a Model S as my only car, and it's worked great for me in winter. Cold temperatures definitely impact range (although this is more due to the extra power requirements of heating the car than anything to do with the batteries themselves). I've experienced maybe a 15% range loss in winter, or maybe as much as 35% in really cold temperatures well below freezing. Shorter trips lose more efficiency because the car doesn't have time to warm up, but then shorter trips usually don't need as much range ;).

When the car gets 260+ miles of range on a charge in summer, then even losing 35% still leaves plenty of range for any situations I've found myself in during ~2 years of ownership.