Lisbon could set its own interest rates to reflect the specific needs of the Portuguese economy.
Portugal would reinstate the escudo so once again the Portuguese currency could float on the Foreign Exchange Markets.
Portugal could negotiate a bilateral comprehensive Free Trade Agreement with World #6 economy the United Kingdom.
Portugal could negotiate a bilateral comprehensive Free Trade Agreement with World #1 economy the United States.
Portugal could seal a multilateral comprehensive FTA with World #9 economy (Lusophone) Brazil via its trade bloc Mercosur.
Portugal could sign a bilateral comprehensive FTA with World #62 (Lusophone) Angola, a major oil producer.
Cabo Verde, a key holiday destination
Guinea-Bissau, an exporter of fish and nuts
São Tomé & Príncipe, a cocoa and coffee exporter
Timor-Leste, an oil and coffee exporter
If you really reckon that Portugal cannot stand on its own two feet globally once freed from the EU, you are very sorely mistaken. Viva Portugal.