Google-oversettingI must say that suites and regular rooms are almost identical. I would not splurge for the upgrade unless they offer to you for free. originally we were allocated at a regular room, but I declined the room due to multiple carpet stains etc.. so they upgraded to this so called mini suite which is almost identical. not really an upgrade, maybe sofa is bigger? hotel actual accommodations and public areas are a little dated for my taste.

Google-oversettingNo they are not

Google-oversettingYes the room we were in had a connecting door

Google-oversettingWe visited in early January and the outdoor pool area was not set up for use, I assume the pool is not heated. They have a very nice indoor pool in the spa. I'd contact the hotel for activities although they do offer some outstanding, high-end dining. Staff is outstanding, you will enjoy your stay The resort is located close enough to the shore line to visit a beach and other attractions over looking the water. Like you, we were in Porto before Sintra and we stayed in Sintra at the end of our trip so we would be close to the airport. Sintra is within reach of Lisbon and many historical sites. I found UTube has some very helpful videos which gave us enough information to decide where to visit and offered some advice from those that travel more than I do. It also showed us what the local like which was great especially for food and drink. We had a rental car in Sinta and be aware that the roads are narrow and many are one way, makes it a little more challenging if you are not used to that type of driving. We tried to use trains or Uber as much as possible.

Google-oversettingI personally absolutely recommend to stay in Penha Longa because you can see Sintra, it is only 30 km to Lisbon, to Cascais. There are many places to see if you stay in that gorgeous Penha Longa which by itself is in my list "must see" + "must feel". And I am sure that the hotel has top level concierge service which will help you to schedule your trips and sightseeing.