Camino in mid-December

You have enough time, but the weather could get in the way. The government position is that you must use the Valcarlos route out of SJPdP. Nothing is open on the Route Napolean. Slippery places will be even more slippery. Intermediate accommodations will be closed, so take food and water.

Buen camino!

Do check the posts in this earlier thread re walking in winter for many helpful links and tips.
https://www.caminodesantiago.me/community/threads/camino-winter-advice.51183/

I have climbed the Valcarlos route 11 times over the past years always stopping for the night in Valcarlos. The latest slog was mid October 2015 at 76. After leaving the Valcarlos albergue at dawn (around 08:00) it took 5 hours to arrive at Roncesvalles, pooped but proud.

In bad weather ie fog, rain or snow I walked on the left side verges of the N135 road and not followed any passages into or through the wood. You can read those accounts more fully here.

Whatever the season or weather it is important to remember that beyond Valcarlos there are neither services nor water until Roncesvalles. Be prepared

Stay safe and Buen camino.

We used the Valcarlos route in 2016 and they even recommended not using the trail because several Pilgrims has been slipped and fallen and hurt them selves, so we walked the road which was fine. Depends on the snowfall and freezing temperatures.