As
@Archangel already said, Guinea-Bissau is basically gone. There wasn't really government control out of a few areas, and the legal status of the colony just remained so because the government didn't want to set a precedent for colonies breaking away. But the important places are Mozambique and Angola, so I'll focus on those.
Something important to remember here though, the colonies were viewed as integral parts of the country. The notion of Luso-tropicalism had become dominant, and Salazar made an effort to move administrators around different parts of the empire in order to forward the idea of one, unified, nation. If the Estado Novo survives the CR and any immediately following coups then you're going to see more of what had been happening. The Portuguese were generally winning the military fight, and were cooperating well with Rhodesia and South Africa. The problem was money, as it almost always is. The Portuguese budget was increasingly consumed by defense spending related to the conflicts in the colonies. In order to counter this the country did open itself to some foreign investment, which it had banned before. But even with generous investment the country's finances are going to continue to be stretched. As the pressure, both public and budgetary, mounts the government is going to get more desperate to wrap up the conflicts one way or another. Asking for more help from SA and Rhodesia could help--Rhodesia certainly proved itself capable of projecting force despite its limited resources--but the budget issues will remain. Depending on how long they hang onto the colonies, and how much foreign investment flows in, Portugal could eventually benefit from the oil resources of Angola. I don't know much about the Petroleum industry, but the Angolan civil war that followed the Portuguese exit certainly limited the production capabilities the region.
To summarize, the government has different routes it can pursue to deal with the issue associated with the colonies, but I'm generally of the opinion that Portugal can hold onto Mozambique and Angola basically forever, particularly if they can exploit the oil resources and reinvest them properly, and continue the political integration pursued by the EN. If they get the oil, and keep on the path of European cooperation that Salazar was a great fan of, they can be a highly important, if politically disliked, member of the European community.