Here’s how to watch Portuguese TV outside Portugal, including live RTP, SIC, and all the other channels. Thank you @anthonylomangino for the excellent idea
If you have a TV set-top box such as an Amazon Firestick, you can add apps to that box. There’s an app called LiveNet TV that allows you to stream Portuguese (and other) TV channels. There are different ways to do it, but here’s how I did it - https://troypoint.com/live-net-tv/
The legality is a bit of a grey area. Here in Europe, my understanding is the law differentiates between streaming and downloading. Streaming is OK, downloading is not. This is a streaming service so is okay - but I am not a lawyer.
Livenet is a bit fiddly to set up, but it works. We now have live Portuguese TV at home. Hurray!