Nice. Do keep in mind that battery is far less efficient in the cold. At freezing temp (0C), efficiency is -20%. I imagine at -6C it's probably in the -25% range.
Yes, I know. When I had a bike with external battery and rode in -10C, the capacity dropped -40%
But I did almost an identical ride week before with the Kenevo (500Wh battery), the consumption and perceived effort were pretty much the same. But it was a bit warmer, +0, and without proper power output numbers it's impossible to really say what's going on.