Hi Frank,
There is another option which will help you in some places but not all, there is some albergues on the Norte in Galicia which are big enough to take groups like yours. There is Baamonde, Sabrado dos Monxes and possibly Vilalba. At Sabrado there is enough space to camp outside in the grounds, they do let people. To stay at these places, if they let you, will require having a pilgrim credencial, and with it having been stamped with sellos at the various places you have stopped.
When i was walking the Galician leg of the Norte i heard of two sports halls, Ribadeo and i think Vilanova(the one after Sabrado) being opened for the larger number of pilgrims that were around. This is usually basic accommodation, mats on the sports hall floor and showers and toilets available. Im not sure how you go about finding out if there is this possibility for you, i suggest using this link as a starting point
http://www.xunta.es/portada.
In the bigger towns, Ribadeo, Mondonedo, Vilalba,Vilanova de Lourenza, Sabrado,there is supermarkets and shops, these are places to stock up with food for the coming day. The only two areas which i remember not having shops or places to stop and eat was the journey between Mondonedo and Gontan, Miraz to Sabrado.
Mike