Hi Tia (Happy new year)
Thanks for your response, I appreciated the generous use of your time.
I've got a couple of quick follow up questions if you have the time.
The Camino de Rosendo seems to go from the south of Spain up to Santiago de Compostela, not anywhere near the side route in question, which is from Foz to Lourenza. At least that's what I can make of the official Camino de San Rosendo web-site.
https://caminodesanrosendo.org/
I'm pretty sure there is a way to walk that section, however, on further research I've discovered a couple of Albergue that are on the Del Norte route between Ribadeo and Lourenza splitting up that long section and that would work for us as well.
Whether or not they are still open, or will be later in the year, may remain a mystery until closer to the time of our walk.
Thanks again
Ross