I wondered about walking north to south too. Last fall, south-to-north, I found it sufficiently marked except for a section of the route just past Arbas and Pajares. I got turned around in one of the cow-patty-storage fields--oops, I mean, the beautiful meadow--past the Bar Casamiro. Couldn't find markings to save my life, until a small stone with a faint splash of yellow paint materialized. Might've been facing the north-to-south direction...
The only guides I know direct pilgrims south-to-north. Wise Pilgrim was my go-to app. This guide, written by "Ender," the man primarily responsible for trail marking San Salvador, and translated by @peregrina2000
, was my best friend on the walk. (I took photos of pages to study in the evenings). https://drive.google.com/file/d/1mm...AJ-06IL-5pLqDKtQ9BOOOsQwVe5sjSuk05r8FqPylDS28
I suppose you could study these in reverse, carefully.
From Ender about that section (south-to-north): "This is a steep descent. It goes through a meadow where the livestock have marked out various trails in different directions. We will go straight down as much as possible, and if there is good visibility we will have a view of the national highway, which we will have to cross at the bottom of this descent." Yes, indeed, the livestock marked this area well!
Camino San Salvador is an amazing, unforgettable journey. I hope you can walk it, in any direction!