a Decathlon?
It is funny: Amount prepared to spend on fossil fuel to drive home and back at Christmas = $$$$$$$$$. Amount prepared to spend on products that enable you to survive/ have fun in an inhospitable environment =$.
I've got a pair of Aldi salopettes, bought them for cold sport climbing days, they are fine but very basic. They'd be nicer to ski in than waterproof trousers over your normal trousers. But if you got into going regularly you'd want to by a nicer pair before too long I imagine. I wouldn't bother buying a jacket if you've got warm jacket you can already use
I've got a pair of Aldi salopettes, bought them for cold sport climbing days, they are fine but very basic. They'd be nicer to ski in than waterproof trousers over your normal trousers. But if you got into going regularly you'd want to by a nicer pair before too long I imagine. I wouldn't bother buying a jacket if you've got warm jacket you can already use, doubt you'll be skiing if it snowing heavily so down jacket be fine, but maybe too warm.Are you about size 7-8 in shoes? I might be able to lend you some very classy 80s ski boots that have been used once since the 80s. Found them to be the most important item when I went skiing as hire boots are uncomfy and don't keep your feet warm. nice warm gloves (or better mittens) also essential.
https://www.aldi.co.uk/en/specialbuys/thur-3-dec/