The night before last, it got down to about 22F (-6C) and when I left for work it was 29F (-2C). The battery was still warm from charging, so regen was working. The car sat at work for 12 hours, most of which was just above freezing. When I left, it was 29F (-2C) and regen was off. This was my first experience with it off. Indeed, the car really rolls! It didn't take long to adjust to it, but 1) half the reason I enjoy driving the car is the fact that regen braking is via letting up on the accelerator pedal and 2) the mapping on the pedal isn't adjusted for when regen is off. For example, when traveling at 40 MPH and you've moved to the brakes and back, you must significantly depress the pedal before *anything* happens. You sort of have to search for the point where you'll get the acceleration you need. When regen is off, you get a yellow light in the instrument cluster. Unfortunately my eyes are being trained to ignore yellow lights in that area due to the constant "hey it's cold outside" light. Based on what I read here, I expected the battery to warm up quickly and regen to turn on. It didn't. Even at a few degrees below freezing, it took 13 out of my 16 mile commute for it to turn on. Really disappointing to drive the car without regen on for so long -- I think I'll need to get back to pressing my place of work for a plug. I wonder if it's practical for the car to allow me to say "keep the pack warm enough for regen for X hours" -- that would make me feel better about the upcoming winter. Without a place to plug in, there'll be a LOT of commutes without regen and I find that very displeasing. Today I left after the car had been parked for 9 hours and I was able to mash the pedal more than I was yesterday. Regen kicked back in after 2 miles... I'm not sure how the average consumer will take to this. Regen shutting off and thus changing the driving behavior of the car seems like a pretty negative point for cold environments. Thoughts / comments?