We have spent a perfect week in Marco's house, the house it is more than enough to spent a good days in Cascais.
It is pretty easy to park you have pretty near good places to get meals and beaches are 10 minutes by car (you can go by cicle also), we go by car and also spent a day in Sintra and also visit Lisbon.
You have a big number of restaurants in the center that is 20 minutes walking (you can go through the beach in a very beautiful walk)