Hi, Dave, welcome to the forum. The availability of accommodation on the Lisbon to Porto segment is increasing in number. The list Diogo pointed you to is the most up to date, in my experience, and it also gives good information on where you can and cannot expect to sleep in the Bombeiros Voluntarios (firefighters). Give us an idea of your ideal stage length and we can help you with stages.
Albertinho has given some great short stage advice on Porto-Santiago here:
http://www.caminodesantiago.me/comm...-santiago-only-doing-10-to-15-km-a-day.23811/
It will be harder to do that from Lisbon to Porto, but are you open to getting shuttled back and forth either by taxi or train?
And as Diogo mentioned, the revisions to the Confraternity's online guides from Lisbon to Porto and Porto to Santiago are done and in process of editing and getting formatted for booklet size. But if you are leaving soon, send me a private message (hit the "private conversation" button on top) and I'll send you the updated version.
Buen camino, Laurie