I’m looking for a region that speaks both Portuguese and Spanish but also maybe another similar, less spoken Romance language.
It can have similar culture but also different, unique culture. Either has to be in Spain or Portugal or nearby them so I could just drive to either country.
Maybe you can try the basque country. They speak basque and spanish (and french) and it’s not that far from Portugal or France.
AFAIK The Basque country’s language has no connection to the romance languages, I don’t think it fits what OP is looking for
absolutely.