probably a little late to
probably a little late to reply, but the Volt can be pre-conditioned while plugged in - you just turn it on remotely 20 minutes before you leave - it will warm up the interior, and top off the battery. when in "Hold" mode, it doesn't recharge the battery - the energy produced by the ICE engine merely keeps enough energy in the system to compensate for the energy being used to drive the car. When running in hold or mountain mode, at 70mph, the ICE engine actually couples with the transmission to provide some direct-drive assist as this is more efficient than using EV power alone (but doesn't change performance (much)). I'll concede, the worst part is, starting the Volt in freezing weather without having access to a charger. The battery draw is huge, trying to warm up the batteries and warming up the cabin. I'm fortunate that, although my office doesn't have charging stations, I am on top of a big 3 mile-long hill. So coming down with a cold Volt, I use the heated seats, while regenerative braking is actually diverted into the heater core to warm everything up faster - but most people don't have that advantage. The disadvantage to my commute is - I use up ~10 miles of range getting up the same darn hill :D (but at least everything is warmed up during the assent)