Originally Posted by
Palal
Depends what you're after. If you want a beach resort, then you need to go down to the Algarve. If you want a city, then stay in LIS and do day trips. Five nights means 3 day to see the city and 3 day trips (Sintra, Óbidos, Sesimbra by car).
Porto is not a day trip. You can split your time 3+3 between Lisbon and Porto, but if this is towards the end of a larger trip when you think you'll be worn out from the travel, then just stay in LIS and enjoy the feeling of the city and not rush to see the sights.
This assumes that things will be back to normal by then, which, as you know, probably won't be the case.
This is too much. OP is apparently flying from SFO to LIS with too little kids. Even with four premium cabin seats, they're not going to want to do much on the first day beyond a gentle stroll and early dinner or maybe a bit of heated hotel pool time. They'll have four days to explore and then need to leave for the airport in the morning following night five. This is about right for Lisbon, with one day doing an excursion by train (I wouldn't try to drive for this) to one of the beach resorts or pretty villages near Lisbon.