First off - you lucky fish! It's so great that you have the time to do this; I'm really jealous!
The Norte is a beautiful walk, but you might have issues with weather and accommodation at this time of year. There have just been a couple of really bad storms in this part of the world, with flooding and warnings of other disruptions (e.g. gale-force winds and dangerously wild seas). However it looks like it's going to be clear for the next week or so, with pretty mild daytime temperatures of about 15°C. But I wouldn't be surprised if the weather turns again at some point over the next few weeks, so you'll need to be prepared.
Clothing: you'll need layers, as it can get cold at night, and not all the alberugues have heating. I'd also recommend waterproof gear, like rain pants and gaters. I always use a poncho, but this is a matter of personal preference. (Most of the major towns and cities have Decathlon stores, so don't worry too much if you've forgotten something, or realise you need something along the way).
Accommodation: the Norte has far fewer albergues than the Frances, and many of them will be closed over winter. For example: I just checked, and the Irun albergue is closed until March. It's the same with the next albergue in Pasajes de San Juan. There is no pilgrim albergue in San Sebastian, and the albergue in Zarautz is also closed. I didn't check much further, but that's just to give you an idea of what you'll be facing. A handful of albergues might be open, but most of the time you'll probably need to stay in private hostels or hotels, which you can book the morning in advance on booking.com. (Speaking from experience, it can be very expensive to do the Norte in winter!)
Let me know if you have any other questions.