Lisbon https://www.airbnb.co.uk/rooms/2563325.
This was in a good neighborhood (Rua das Pretas 7) close to a pedestrian street, and some rather touristy restaurants. We could walk down to the river and to Barrio Alto in 15 mins each. It was a decent apartment, not fancy, the queen bedroom was away from the street so not noisy. Two toilets, with a shared shower, which was nice for 4 of us sharing!
Places we loved:
Cafe Fabrica - Rua das Portas de Santo Antao 136. Hipster coffee! and a lovely vibe. Good breakfast food too. Near the apartment.
Brunch Cafe, Rua da Alfandega 120 (near the river)
Jardin Principe Real - lovely little open air cafe under the big fig trees. The park itself is nice, not spectacular. Small fenced playground for littler kids. The botanic gardens is under renovation and closed so we ended up here eating a delicious cheese and meats plate and drinking wine.

Rented car from Europcar which was just a 5 minute walk away. Nice and easy pickup of the car. (the return in Albufeira was less charming - we thought we had a one hour window of lateness, turns out to be 20 or 30 mins. We talked our way out of paying the extra day, but the Europcar person was less than gracious!)
On the way to our next stay we stopped at Praia do Guincho - great surf, miles of white sand, cute little cafe on the far end in the small ravine (there's a smaller bar/cafe on the beach itself - once you get to that, there's a boardwalk in front of it - follow that and you will find the other cafe)
- Near Sintra: Ecoaldeia de Janus https://www.airbnb.co.uk/rooms/9135932

This is a wonderful farmhouse that looks centuries old but was in fact built in the last 20 years by a collector who had accumulated all this amazing old wood, stone slabs and artifacts. The family room was gorgeous, and the house cats slept in there with us much to the kids' delight. there were numerous WOOFers and interns to chat with,as well as a few other travelling families to meet over breakfast. some nights we ate in the co-op's restaurant in the village , Janus - (Cooperativa Integral ALDEA)- delicious! and once we cooked in the wonderful farmhouse kitchen. lovely to have space to wander, shady trees with hammocks, a lovely garden, chickens, pigs, sheep etc. And a short drive to Sintra for the day, or 10 mins to incredible beaches (Praia Grande has dinosaur footprints in the cliff, good surf, more built up area with restaurants).
We really highly recommend this place. 50 Euros per night for the room, including breakfast. Shared bathroom was very clean and rustic chic!
- Sagres - Pura Vida Divehouse (http://puravidadivehouse.com/)

Sagres is windswept and white washed and only minorly touristed - mostly surfers and divers, a couple of large hotels and resorts but not too much. We loved this "hostel" - it only has 2 rooms with 4 beds each, we took up half the hostel. A lot of the time we had the place to ourselves - a well equipped kitchen, comfy living room, colorful porch and lawn, two friendly dogs.It cost 25 Euros per person per night (so 100 total for our family) including breakfast.
A 10 min walk to the closest beach, and 30 min drive to many incredible sandy beaches with waves. Some more developed ie with a few surf shacks and great casual cafes, others with nothing but a single simple food joint and miles of beach. We visited a different one every day - Praia do Beliche (pictured), Praia do Amado, Praia da Bordera. All great, in different ways. You can rent surfboards and body boards at the second two. Beliche is calmer and just generally scenic!

- Porto (https://www.airbnb.co.uk/rooms/19425736). Cost USD 100 per night.
This was a "managed apartment" so was well appointed and empty of owner's stuff. It was large, and walkable to everything - probably 30 mins to the river if you didn't get distracted or wander up and down every windy alleyway like we did. Even though there was a subway stop around the corner, we never used it.
Places we liked:
Letraria Craft Beer Garden
Livraria Lello - but the line and the crowds made the experience less thrilling!
Casa Marlindo for a yummy tapas lunch on a sloping cobbled street
World of Discoveries - museum about Portuguese exploration - fascinating and kid friendly. Sounds kitschy, and touristy, but was actually good
Outside of Porto we went to the Leca da Palmeira - rock swimming pool on the beach - lovely!! and the nearby Mercado Da Foz do Douro and the yummy pizzas at Peco (at the back right of the market)
- Viseu
Both Porto and Viseu were in the "unplanned" section of our Portugal trip. I got excited about the Ecopista do Dao, a former railway now bike path, and planned a few days around that.
We stayed at a loft apartment in an old building that was right in the old town, so super well situated. The only negative was that with the sofa bed open there was very little communal living space so we just had to pack it away during the day. Every apartment in the building has a different layout so would probably depend on which one you had. It has the annoying name of BeMyGuest by Besolution - Loft Guesthouse, but was cool regardless.
The highlight was the bike ride. We rented bikes from the lovely Pieter at Quinta da Abelenda, which is actually at the other end of the Ecopista. He brought the bikes up to Viseu, we rode down to his farm, then he drove us back up to our car! Great service for 25 Euros per person including the bikes and the driving us around. Given that you couldn't rent kids bikes at all in Viseu, this was a life saver and worth the money for the experience. You can also stay at the Quinta, and get the same deal - they drive you up to Viseu, and you ride down.
There are numerous bar/cafes along the route in the old train stations, some with little playgrounds. These make an ideal stop along the way.
On another day we went to the local swimming pool which was huge and had fun water slides and lounges to lounge on. There was also a local bakery with delicious chicken pies!