My wife and I are going to Portugal for three weeks in October. We will be touring by car. I would prefer to use Google Maps for walking instructions and driving. Google Maps walking offline does not work. I was wondering whether it is better to buy a Sim Card in Portugal or here in the US?
Get one when you arrive. There are SIM shops in the airport in Lisbon. Quick and easy.
I think it's always best to buy it after arrival, preferably at a dealer near your stay. Sometimes, there are activation issues, and the person in the store can provide you with immediate assistance. How do you get help if the sim that you purchase in the US has an issue?
I do not suggest buying the same at the airport. They might be a little bit more expensive. Moreover, it may take up to 90 minutes for a sim to be properly activated especially if you don't know what you're doing. I would rather wait in the comfort of the hotel than waiting around at the airport.