Re: I carry a whole bag in winter
You should look into Liquid Snow Chain Spray.
Different use cases. Getting out of being stuck vs driving. You usually get stuck on ice or very compacted snow where snowsocks, winter tyres and even snow chains may not be enough. You need to get out to somewhere where you can drive with your current tire set. The classic remedy is sand and that is what you can replace with cat litter.
Driving on snow for a period of time? With a spray-on gimmick? No thanks. I saw the tires on that Seat in the video, in any European country trying to get onto the road with this tyre in snow would be an immediate 3-6 points on your license (*)
Disclaimer - all of my cars have either a proper set of winter shoes or all-weathers which are known to be good up to 5cm. Even the UK resident ones. Even my 4x4 has a set of proper winter shoes to use between November and March. I use them in proper snow though (the kind you see this winter in Europe). I also have a set of proper snow chains in the boot just in case (even on the 4x4). And 25l cat litter bag too.