Another +1 for the Aldi Ski gear!
We bought ski jackets for the whole family. We don't need them at home in Brizzie, but we bought them specifically for when we travel. They live in a duffle in the camper trailer.
I agree, layering makes a big difference but the ski jackets are quick and easy, especially for the kids, and especially if it's particularly cold right when we arrive to set up camp somewhere.
Cheers!
Jono.