I was in far better shape when I was preparing for the Camino Frances. Fear is a tremendous incentive. I have been planning all year -- first the Via Podiensis in France, then Wales, then the Aragones/Primitivo, and finally the Portuguese. I had various buddies who, for many good reasons, choose other paths.
One begins any venture by checking in at the watering hole of all the caminos, the Camino Forum, where I (mistakenly) set up two accounts: https://www.caminodesantiago.me/community/
The decision: The Caminho Portuguese Interior (CPI), which is not the "Central" Porto-Tui-SdeC, nor the popular seaside "Coastal." CPI travels 400 km over the hot interior mountains, through the "Duoro" wine region into Spain, connecting up with the Via de la Plata via Ourense.
Aurelio Simoes has offered invaluable assistance with weather, lodging, local information, bus and train schedules. I cannot credit him enough.
Once I decided on the CPI, there was much investigation, guided primarily by Caminho angel Aurelio Simoes. I have translated various accounts in Portuguese (Brazilian and Portuguese), Italian, and French, some from Wikilocs, many from Aurelio. Best are Brazilian peregrino extraordinaire Oswaldo Buzzo. His 14 day walk on the CPI may be a record. I used Chrome to translate each day of his diary to English.
And the notes of Italian, "Bruno"
The Camino Portuguese Interior site www.cpisantiago.pt/
Where to sleep in Portugal
Here's a general itinerary of "Grace the Pilgrim." I am guided by the Portugal segment, but am projecting a different set of stops in Spain.
1, Viseu - Almargem, 16 km
2, Almargem - Ribolhos 25 km
3, Ribolhos - mizio/penude/Lamego 32 km (+5 km taxi)
4, Lamego - Peso do Regua - 12.5 km steep
5, PdeRegua - Bertelo - 15 km steep
6, Bertelo - Vila Real - 12 km steep
7, Vila Real - Parada de Aguiar - 27 km easy walk
8, Aguilar - Vidago - 23 km
9, Vidago - Chaves - 18 km
10, Chaves - Verin 29 km. (SPANISH BORDER)
11, Verin - Xinzo de Linia - 35 km
12, XinzodL - Allariz - 21 km
13, Allariz - Ourense - 24 km
14, Ourense - Castro Dozon - 38 km
15, Castro Dozon - Bandiera 36 km
16, Bandiera - SdeC - 34 km
You can't have too many maps. There is no book for this caminho.