Its better to get cvt oil change in chilly winters.
Drain oil when car is hot, park it for an hour or so and then fill back again. This is what I did and it is a standard procedure.
I connected obd port number 4 from top and 5 from lower side with a small wire. Meter went into temperature check mode. I moved gear lever to R 5 seconds and D 5 seconds, then I moved it rapidly between N and D like 10 times. There was a point when D appered at all gears even at N. If D on the meter cluster blinks then temperature is higher then 45 degrees and if D becomes stable then you can open drain nut and check the oil level. Surpisingly nothing came out (toyota stealership did cvt oil change by opening pan at 55k kms and added less oil). I then added 200ml oil more, did it again and oil was just dripping so cvt oil was at optimal level now.
One can connect toyota techstream and know about the temperature of cvt oil through that as well.
Toyota stealerships won't bother this much coz they want to free their service bay as soon as possible. Proper cvt oil change will take 3 hours.