Hi i am doing this of my rickety mobile so cant give you precise details but there are albergue de peregrinos(adp) in Matoshinhos( portuscale association), 26-28 km on you have an Adp in in Povoa de Varzim, 19-21km you have a Adp in Marinhas(red cross building), 23km an adp in Viana da Castelo(in a covento), 24km on a Adp in Caminha. If you stick to the coastal route you have a ferry journey to Spanish soil and 4km walk to Guarda where there is a Adp(try tourist info), you then have 21-23 km walk to mougras where there is a private albergue 10 euros which may have been originally a peregrino only one but the xunta let it go and someone else has taken the reins. Here my memory gets patchy, but about 20km + on in Nigran there is a peregrino option, then about 25km+ in Friexe is a peregrino option 10 Euros this is on the alternative way to Vigo and at a higher level- so good views of the Ria. Then next 10-20km(?) you are back on the main route at Redondela.
Good luck.