I think Lisbon was on the radar a few years ago, but I get the impression it may have blown it. According to folk I know who were looking at it, they had issues with the 'work ethic' of locals (read into that what you will) and high tax.
what I read is when worker's lives arent threatened (by deprivation of health care) we make sensible decisions about balancing a commitment to an employer with our commitments to family and community.
I have no clue about Portugal, just wanted to point out these things are independent, e.g. in Norway/Denmark high productivity ("work ethic") while at the same time leaving the office on time and closing shops early. While Germany does not threat workers life but people stay too long in the office and shops are open to long - but it gets better.
Well Cloudflare has an office there, where their CTO is.
I don't know about start-ups, but I think Portugal in general is still growing in attraction for remote workers. Great climate, still cheap and beneficial tax laws.