It isn't possible to directly warn you of something that doesn't exist.
Cold weather effect on batteries is long known, ask the rac/AA etc. their callouts for starting problems surge during every cold snap.
Yes, EV batteries are less efficient in cold weather and range can drop by up to 20% depending on how cold it is. Tesla's like all EVs can be fitted with a heat pump which helps combat this by about 10%. However in extreme cold (-15c or below), even the heat pump will struggle, and Tesla has had an issue with the pumps on the 3 and Y which are failing. They fixed the issue once, but it has recurred.
So their legal/marketing department didn't work together enough to combat possible false range claims, they should especially in countries known for cold winters added an line about winter weather and the effect on range.
The figure of 50% is a 50% reduction based on how they are advertised online. Everyone knows that the range stated by manufacturers is as accurate as the MPG quoted on ICE cars.
What the car will do is adjust your predicted mileage and tell you how many miles you are doing per kwh. It will then point you to a charger when it is needed. Range changes hugely based on how and where you are driving, the heat / cold issue is just another variable.
So they didn't got their terms and claims right, the best example is broadband, they advertise an certain speed but before you buy it tells you more accurately what speed they expect you to get. The same couldbe done by tesla on the order page, that is shows the reduces expected range on cold weather for example.
The police have charged the Tesla driver with attempted murder of his wife and children.
I did wonder about the crash and if the car had suddenly shot off the cliff edge at speed, and in a cartoon fashion simply dropped vertically landing on 4 wheels. That felt like the only way driving off a cliff could be survivable. Didn't expect it to have been deliberate though.
It doesn't have to be deliberate for the driver to be charged with attempted murder, for example an case of
smalldickenergy@getalife.com can lead to the same charge if the police checks his tyre marks speed etc. and comes to the conclusion that he was driving much to fast/irresponsible etc. useally a combination of those. We have seen similar convictions across europe, uk and elsewhere for example if someone manages to speed with 80 mph where he/she is allowed 20mph and kills someone in the process, in most countries it goes automatically into an murder charge then because of the irresponsible behavior means the driver took so much risk that a murder charge is justified.
If you own one of those to clear your driveway, you're earning too much money!
Really not the point at all.