If battery is "too cold" then power will be used to heat the battery, and either charging will be slow, or not-at-all (until battery warm enough).
It will still draw max power (well ... not if you are at a Supercharger) - in order to heat battery
I don't know how cold the battery has to be before some power is used to heat the battery.
TeslaFi etc. may be able to show that. I cannot find a single charging occasion where the temperature was Properly Cold ... but I managed to find a few around 0C where the Charger Power was up to max within a minute or two, but the Charge Rate took 10 minutes to get to max.
Here's a Teslafi graph from last night. Temp was hovering at around zero. You can see that the first 10 mins or so of "charging" was battery heating. I think at a few degrees more, it doesn't do this, so I'll guessing the heating phase is engaged when the temperature is somewhere 0 and 4 deg C.