MotorTrend has been conducting a long-term test of a Volt and, in the latest update, MT has compiled some interesting data on winter driving with Chevy's EREV. It seems the HVAC system does more than simply equalize the air temperature to what is set on the climate control. MT found that when the heater was set to 75F, the cabin temp stabilized at something closer to 65 degrees. However, the footwell temperature reached about 85 degrees. Apparently, a toasty footwell plus heated seats makes up the difference and kept Motor Trend's Frank Markus perfectly comfy (when he was dressed for winter weather, at least).
Also in the long term update is some info on the pre-heating performance (or lack thereof). It seems this feature isn't up to the task of raising the cabin temperature in a reasonable amount of time. After 35 minutes of pre-heating, the cabin temp was a frigid 39.1F and the footwell only a slightly warmer 47.9F. It's not clear whether this is typical or if something is wrong with this particular Volt, but MT plans on taking it to the dealer if things don't improve. To get all the data as well as some nice graphs, click here.
[Source: Motor Trend]