You could see 2 countries in 2 weeks if you start from Porto, it could be done easily in 2 weeks, taking a day or two to explore the amazing city of Porto before the start, then 9-10 days to walk to Santiago, and then a couple of days after the Camino to stay in Santiago or head to Fisterra/Muxia. Portuguese Camino is easy for your feet, infrastructure is great, warm weather in April, very popular but not so busy as other routes.