I don't know if you know the other way. The southern side is not much better regarding shade, stores, toilets etc. There is not much left from Ruesta for the same reason.
It is always more complicated to walk in the opposite direction. If you plan such attempt it's better to google a bit. Just with the word Tiermas you can find many pictures with the ruins of that place. Escó is a bit trickier, but google maps offers a clear hint "Pueblo abandonado / abandoned village" so no surprice to find more ruins
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There should be some life in Sigües, Asso and Berdún still (it's 20years that I have been in the last one).
Did you walk that after Artieda?
@Amy
Maybe a cap is not necessary. The bus Pamplona-Jaca follows more or less the northern route
Consulta los horario de la línea de autobús Pamplona Jaca, gestionado por la Burundesa.
laburundesa.com
hitchhiking can also work, since anybody knows there's not much help in this area.
Yesa to Sangüesa via Javier includes some road walking. You should have the map at hand, because signs are few to none in the beginning and they are different (wooden poles with yellow ring for the camino), because the southern camino is still some km away.
Sangüesa to Liedena is mainly on the road, maybe the last km is on a (gravel/dirt) track next to the road. At the entrance you find a hotel and restaurant. Leaving Liedena and all trough the Foz is on a track, than some asphalt (~200m) and dirt path/track till you enter Lumbier. You have a restaurant on the road crossing. next is 1-2km tarmac before you walk on tracks for some km. From Aldunate to Izko you'll hit the old national road or you look for some connecting path to the alternative camino via Rocaforte.