Of course!
Due to the arrival and departure times, you should have at least a week, but generally, you can spend anywhere from one week to six weeks on the Portuguese or French Camino de Santiago.
Unfortunately, neither a train nor a bus runs permanently parallel to the routes, but it is indeed possible to combine different sections.
For example, you can fly to Lisbon, walk from there to Coimbra, take the train to Porto, walk to Vigo, then take the train again to just before Santiago, and finally fly home from Santiago.
With this plan, you can visit four beautiful cities in a 2.5-week vacation.
Alternatively, you can shorten stages along the way if they seem too long or skip one that isn’t very scenic.
Of course, it’s tedious to find the connections and first figure out where it’s even possible to shorten the route. Both in Portugal and Spain, there are countless interregional bus lines, and unfortunately, very little overview of the routes.
But this is something I would be happy to handle for you if you book my travel consultation.
Can you take shortcuts on a pilgrimage?
If you ask a “true pilgrim": no.
Shortening the route is highly frowned upon among pilgrims. Yet, I often met pilgrims in Porto or Saint Jean who told me they would never take shortcuts because it was very important to them to have walked every single kilometer themselves, only to later encounter them at some train station. At the latest, when the combination of rain and a 30 km stage appeared for the second day in a row, those principles tended to be relaxed.
Ultimately, everyone has to decide for themselves whether they want to feel like a pilgrim while walking the Camino and what makes a pilgrim for them.
To get your Compostela, you need to have walked the last 100 km. Before that, you can take as many shortcuts as you like.