Backwards on the Camino del Norte?

When I walked the Norte in in 2013, baggage transfer was not an option, I had never heard of it until we joined the Frances for the last leg of the camino. Since then I have heard of a couple of companies starting up and doing it, but I would be surprised if you could find a company that did it consistently along the route in reverse. While walking I met a wonderful couple who had started walking from France and had made it to Santiago and were now walking back home in reverse along the Norte. He was 82 years old and said he was not allowed to say the age of his wife, but "between us we have 150 years" They had found navigating in reverse quite hard, and so had bought a GPS, to help them , along with some detailed maps. I suggest you keep your packs as light as possible and be prepared to carry them yourselves. Bilbao to San Sebastion is a lovely stretch with fantastic scenery, it should be a great walk for you. Buen camino!