I will most certainly be walking this route soon. The Camino Invierno was recently made an official route to Santiago (news in Spanish) with the aim of relieving the pressure on the Camino Frances from Ponferrada. It is 261km long and runs underneath the Camino Frances. If you were to walk it now, the chances are you would be walking alone for the majority of the day. The only accommodation available are pensions and it can be expensive as there are no municipal albergues open just yet. In time, and when the numbers of pilgrims increase, albergues will open also.
The below video has been recently uploaded to YouTube and shows many photos of the Invierno.