Nothing special needed for a Winter camino, Aljay. It's a beautiful time to walk, easily done and at least on Frances you'll have plenty of company.
Other camnos - Primativo, Aaragones, Portuguese, Invierno and San Salavador - are also easily walkable in Winter. They're more solitary of course - w/ days of only the sound of your footsteps and wind - but it's actually quite wonderful ; ) And you'll still find accommodation available at the end of most stages.
Obviously you'll want to check forecasts before crossing higher passes - but at least for me, on all the above caminos, they've been 99% snow-free in Dec, Jan, Feb. (Winters have been warmer than usual these past few years) In 3 times over O'Ciebro, only once was there snow, a few inches, and everyone tromped up just fine.
You can expect a weather mix - warm sunny days, cold rain/snow showers, wind, morning fog, etc. I use gaiters, thin wool sweater, simple waterproof jacket/pants - add some sunblock and you're ready to go ; )