Lots of questions

Thank you all!

Hello, We are hoping to move after the UK summer, so we are in the process of going through all of our belongings to work out what to take, scrap, sell etc. I've hit the winter clothing box and I'm a bit stumped. I know it gets quite cold in winter in Adelaide, but is it worth taking thermals, water proof suits for the kids, waterproof over trousers, thick winter coats etc or would we get away with thinner winter coats and wellies? We are planning on taking the least possible and not having a container or anything! Thanks