I was checking on my battery and let it warm up to 24ºC in a hover before flying initially. Battery temp wasn't an issue but in viewing my cells 2 of them were in yellow as their voltage was a little lower than the other 2, this was in my hover time. I can't exactly recall the battery temperature but it was fine.
I have a client who wants me to operate in possible -35 to -40ºC temperatures and I am having severe reservations. I plan on getting the
Inspire 2 and think the heated batteries may make it possible but without the CrystalSky I don't think it's possible with a normal ipad or the like. Plus, I don't know if I can manage that temperature!