Traveling to Portugal September 2018: Need Advice

Ignore the vacation part.
Prioritize what is important in a retirement location for you.
Decide upon possible retirement locations and focus your visit.
Lengthen your trip.

Sounds like you may be making the same type trip I did in spring of 2015. I moved here 4 months after my scouting trip and love it.

The Lisbon area is very, very different than the Algarve. The Algarve is much more spread out with fewer things to do IMO. You would need a car to live in that area. That said, English is even more widely spoken than in this area and if you play golf you might like it. When visiting in 2018, you would also need a car.
The Lisbon area has great public transport. I've lived here for two years without a car and am happy using public transport and walking.
You might want to plan on checking out other towns along the commuter train line between Lisbon and Cascais. There are a number of towns that are smaller with fewer tourists. If you really want rural, the Tomar or Coimbra areas might appeal to you. But to live in those areas you would need a car. Pretty much any place you choose to live would have basic services.
If you have specific questions, feel free to PM me. I would be happy to help if I can.

Thank you for the information and advice. Since we have never been to Portugal before, it can be daunting to try to figure out where to explore as our main resources/information is coming from Google searches, blogs, etc. Again, thank you for taking the time to respond to this inquiry.

I second Kathrynj's remarks. Communities along the railway line that ends in Cascais would be great locations to live as an ex-pat. We stayed with a local couple in nearby Estoril for a month or so and found Cascais a great center for banks, food and other shopping, sports centers, health centers etc. Easy train access to Lisboa and seniors are entitled to 50% discount on train fares. After travelling for 6 weeks in Portugal (with locals) we realized that inland locations would be much more difficult to live in due to language barriers. In spite of not speaking Portuguese we found all the citizens to be very warm, friendly and welcoming and we will always hold this country in our hearts.

Thank you very much...I appreciate your comments/suggestions.

Public transport on the Algarve is (i'm thinking of a polite description......) , erm , weak.

There is a decent railway from Lisbon to Faro which manages to miss most of the important places in between. The coast line from Lagos to VRSA on the Spanish border has a decent level of service, but the actual trains are a bit rustic and guess what, half the stations are a long way from the village they claim to serve.

Which leaves the buses. There are some very nice long distance buses to Lisbon, in many cases duplicating the good trains although the route from Lagos is useful because the rail route involves quite a detour. But local services are a quite erratic and some routes stick to the main road which runs inland some distance from the coast and misses the coastal villages (there's a trend developing here....). The big operators from northern europe have set up around Lisbon and further north but the Algarve business is very seasonal and none have thought it worthwhile. This website was put together by a frustrated british resident and makes more sense than the official sites http://algarvebus.info

Faro airport has a decent all year round service with flights all over northern europe which may find better connections for family and other visitors than travel via Lisbon.

Inhabited areas on the Algarve are a bit patchy. Some have a genuine all year community, supplemented by many retired british and other northern europeans. Others can be dead during the off season. One thing to think about is that if the Brexit negotiations go as badly as many expect, a lot of the brits could be forced to sell up and leave, which may mean a drop in property values around 2019-20.

Thanks very much for the information. I really appreciate it.