I have the exact same problem!! I do have a second charger at work,
and for some reason, this rarely happens when I use the work charger.
Could it have something to do with the battery charger?
I live in San Diego, so the battery has never seen weather below 45
and the temperature issue that you mention is not the problem.
Jeff Hasty
PS: I love the bike. I had to change the front chain ring and rear
cassette because it was geared for a top speed of around 20MPH. With
the 1000W motor, the gearing should be such that top speed when
pedaling is around 28. It's an awesome ride to work, but the annoying
plugging in and out several times, sometimes consuming up to 15
minutes in the morning, needs to be addressed.