This is becoming more and more of a problem!
More and more people are interested in holiday rentals on the Linha da Cascais and there is not a lot of concise clear info available.
I am actually in the process of investigating the possibility of doing something in this area and hope to have a few meetings in Lisbon in a couple of weeks about this.
I've searched the Portuguese web:
Have a look at these:
- http://www.vilabicuda.com/en/vila-bicuda.html (Not close to town)
The Cidadela is close to the centre of Cascais -about 6minutes walk. It is an old hotel. I stayed there for a couple of nights a couple of years ago! Very quaint but good service. They have apartments as well.
(Carcavelos is half way to Lisbon on the train line about 15 minutes from Cascais) There is popular beach there. The famous St Julian's English School is also located there.
Parede is one stop before Carcavelos coming from Cascais
Oeiras is one stop after Carcavelos coming from Cascais.
Also have a look at this site which appears to do exclusive rentals and is associated with Christie's!