As a great fan of Sagres and Cabo Sao Vincente, I wouldn't mind some railay extension over there.
But getting that HSL corridor from Valença - Faro should be the priority. It should have a strong structuring power.
The only way to gain market share in the short and medium run on yearly summer migration would be to develop motorail services from 🇫🇷 🇧🇪 🇳🇱 🇱🇺 🇩🇪 🇨🇭 . Kinda more upmarket version of Optima Villach - Edirne.