Cascais Portugal

I’m in the early phases of planning a family trip next summer. We’re two middle-aged couples and two teenagers. We are from the US and travel to Europe often, for this trip we’re looking for a relaxed beach-y trip that still offers some architecture/history, great food, some adventure for the teens and reasonable prices. Cascais was recommended by a few travel guides but it seems to be focused on a day trip from Lisbon. I was wondering if there was enough to do if we spent a week in Cascais as a sort of a home base, with potentially day trips to Lisbon, Sintra, Obidos, wine tours, etc.

I wanted to see if people thought if a week in Cascais would be worthwhile of if we would grow bored quickly. Also would love and recommendations while we are there, particularly for any nice resort style hotels or beautiful rental properties for us to stay in.

If not Cascais, would also appreciate recommendations for similar destinations that fit our criteria.