Heated seats and steering wheel have a much lower effect on the battery/range than the heating system.
My 85X Enyaq is back to the dealers tomorrow morning, the 12v battery is rubbish, it’s simply not up to doing the job it’s supposed to do. For the last 2-3 weeks every time the car is left for more than say 10-20mins when I come back to it the auto door unlocking/locking and the door handle sensors fail to work.
Luckily it still opens with the remote but I’ve seen several reports of owners having to use the mechanical key to get in as well as the battery being so discharged the car will not power up. I’ve checked the battery voltage and had it read from 11.4v to 11.6v
The cold is having a big effect on the car, 2 weeks ago when it was about -2.5c apart from it not pre-heating and the locking system failing both heated seats refused to work until I’d done about 15 miles/25 mins driving. I stopped off for a hot drink and a sandwich for my son and I and when we got back to the car they started working again.
The next day the passenger seat failed again and is still not working. I fully charged the car last night, had 242 miles range reported this morning, after doing 44 miles today (mainly A roads and not short journeys) the range is now down to 181 miles and it’s already used 26% of the battery.
Please excuse spelling/typos. Apart from being a clot it turns out I had one on my cerebellum that's now causing various problems!