Roncesvalls to Santiago
Hola peregrino,
"A Practical Guide for Pilgrims" by Millan Bravo Lozano gives 31 daily stage maps from St Jean to Roncesvalles.
The Lonely Planet Guide to Walking in Spain gives 28 days.
Some pilgrims walk 15km - 20km a day, taking anything from 38 days to 45 days to walk the distance.
I walked from Roncesvalles in 2002 (at age 56) and did it very comfortably in 27 days - walking a bit further on the days through the meseta.
Hope this helps.