well, the camino del norte is physically much harder, and there is a lot more road walking. Before Santander the "pilgrim" type accomodation is pretty scarce, and it is not a cheap area for other accomodations. However, you will meet more locals who are not pilgrim saturated, and much of the way is very beautiful. You do need to be more independent, if that is the right word. Not invariably good waymarking, food shops sometimes a long way apart, and you will be walking on your own. You will meet some pilgrims, but not a flood of them. The weather is more coastal, as you would expect, so not as hot as the
camino frances. Your spanish will improve!
I walked from Le Puy en Veleay to St Jean Pied de Port, then along the pyrennes to Hendaye, then camino norte and branched on to the camino primitivo. It came as a culture shock when I reached the
camino frances near Santiago, with so many people........
I see you are cycling. I think that is probably a good way to do the camino norte as that will be easier for short détours for accomodation, but you may need to get off and push sometimes unless you are very fit ;-)