The festive jumper that actually survives Christmas is a rare beast. Fair Isle and Nordic knits, however, are the exception: seasonal without veering into gimmickry, and warm enough to see you through the bitterest months. They’re the pieces that let us feel, by turns, as though we’re bustling about Brambly Hedge or starring in a moody Nordic noir – and frankly, that’s the kind of range we want from our knitwear.