These are my bookings around the same time. I don’t normally book this much in advance but it seemed prudent on this occasion. Private rooms except two nights; used Booking.com for most and contacted a couple directly (Sandra and LaCala).
Day 0 (22nd): Porto - booked Duas Naçoes (private room, €42)
Day 1 (23rd): Porto - Vila Chã (26km) - Café Sandra (private room, €30)
Day 2: (24th) Esposende (31.5km) - booked Eskimo hostel (private room, €40)
Day 3 (25th): VdC (25.1km) - booked Alex Point (private room, €42)
Day 4 (26th): VdC to Caminha (26.8km) - booked Bom Caminha albergue (private room, €45, free cancellation)
Day 5 (27th): Caminha to Oia (16.4km; ferries at 7:30, 8:30 etc) - booked LaCala Inn (albergue dormitory)
Day 6 (28th): Oia to Baiona (22.4km) - booked Estelo do Mar (albergue domitory, €16)
Day 7 (29th): Baiona to Vigo (25.3km) littoral - booked Pension Buenos Aires - €45, free cancellation