I have family, but they are based in Germany, but everything depends IMO if your kids are able to speak Portuguese or not. That for sure would impact your budget for education. Living in Setubal/Almada, you can plan a 700-800 euro/month rent, 300-500 for supermarket, 100-300 transportation and then education in case your kids need a private school. The costs with transport may vary if you have to commute daily to Lisbon, if you use car or not and etc.