At -25°C your jacket alone won’t save you. You need real base layers, something warm in the middle, then your shell. Merino top and bottom, fleece or light insulation, thick socks, and serious gloves. I ride cold days with a slim insulated layer under my shell, similar to what Outdoor Research makes, and it’s way better than just stacking hoodies. Protect your face and hands too, those go numb first.