True. I think the point that the SR, which doesn't have as much range as the LR to start with, is proportionately more affected by the cold, is worth making though.
Certainly nothing wrong with his battery, but it could come as a shock if you weren't expecting it. If you are, you know to plan for additional charging time in winter if necessary, and to think about contingencies in advance. I think the worst thing you could do is to reset the GOM to factory specs and think you've solved the problem and your range is back to summer figures.
I think the best thing to do in winter is to try to find an AC charger to sit on while you do whatever it was you went to do, and also to identify a DC charger on your way home just in case it's looking tight and five or ten minutes on that will get you home in good order.