We were 4 people staying at Joanas place for 10 days - it would have easily fit for 10 people because it is super spacious.
Pros:
Great Pool, lovely view, huge BBQ place and Pizza oven, big, airy rooms, big living area and fully equipped kitchen, perfectly located for beach hopping, surfing and city trips - we had a great time!
Ribeira d‘Ilhas (one of the main beaches in Ericeira), local restaurants and small supermarket: 10 minutes walking distance
Big supermarket: 10 by car (we highly recommend a car!)
Cons:
Big main road going up the hill right in front of the house (traffic noises day and night), sewage plant 500m away which you can smell sometimes (incense candles helped a lot) and a big dog next door that barked a lot.