Hmm sometimes life is hard.
Any way than I should suggest take the metro out of Porto to Vila do Conde and walk from there (nice old aquaduct you'll see ) to São Pedro de Rates about 18 kms. 4 kms more brings you to Pedra Furada give him a call on beforehand. 00351 917 838 144 if rooms are available
From there it is about14 kms to Barcelos and from Barcelos to
Casa da Fernanda 20 kms
The next day I advise you only to walk to Ponte de Lima from there 14 kms and stay there ffor the night because the next day is the hardest,
Ascending and descending the Labruja mountain 18 kms to Rubiaës
From there you are on the regular caminho schedule
Rubiaës to Valença /Tui. 20/23 kms
Valenca/Tui o Porriño 20 kms
O Porriño to Arcade 20 kms
Arcada San Amaro 20 kms
From there it is figuering and puzzling out and about a bit but I come out on about 10 to 11 days to Santiago as I counted well
I have a look in my picturealbum how we coped