Depending on your ability to work remotely, I would make the "case" that you should consider Portugal . Lisbon and Porto are super popular with ["digital nomad"] remote workers who work for international companies so earn in USD but spend [much less] in Euros for a superb lifestyle. There's a reason @paddycosgrave moved Web Summit to Lisbon. It's one of the cheapest cities in Europe and [unlike Barcelona] everyone sp…
Also education is not very convincing (considering op might want a family). Universities in Portugal are not that great nor renowned. Many qualified young people go work abroad by lack of local opportunities. I've also heard that healthcare is messy if you can't pay. It doesn't sound like a healthy country to me.
I guess Portugal is good enough if you just want sun, decent food, cheap QoL and good internet, but I wouldn't consider it a thriving intellectual place by any means. But maybe in OP's words, good intellect = finding a sufficient concentration of other engineers. Then it might be enough.