Should Madeira or the Azores be added to a mainland Portugal trip?
Add Madeira or the Azores only when you can give them real days. They are not quick extras to mainland Portugal; treat them as a serious route choice or save them for their own trip.
Answer
Madeira and the Azores are part of Portugal, but they do not behave like a spare afternoon after Porto. Flights, weather, car logistics and the slower rhythm of island travel all ask for space. Mainland Portugal already has enough for a full trip: Lisbon, Porto, the Douro, the Algarve and smaller towns can easily fill two weeks. Add an island when it changes the purpose of the holiday — hiking, volcanic landscapes, ocean air, dramatic roads, green weather, slower coastal days. If you only have a few leftover nights, the island will likely feel like a costly detour. The better choice may be to let the mainland breathe and come back for the Atlantic version.