Eroski site would say 36 days, with no rest days. Editorial Buen Camino 34. So if you consider 5 weeks being 35, it is a bit tight. But who says you can't skip, for example, the 2 Days lokned norte with Primitivo, or the bit into Bilbao and out of it, or, or or.
To me these are 2 very different routes. One quieter, more about long distance walking that "spirituality" and "camino magic"' with spectacular views od the sea and walking through clouds in mountain ranges. Tje other busy, busy busy, with lively rolling hills and big sky in the Meseta, more socialising and more monuments, churches and history, perhaps more sybolism. I am glad I have done both, there really is no wrong choice, until you have them both under your belt and which is for you.