In the long term, I'd check the discussions on the durability of standing colonial empires. Conventional wisdom is that the Second World War devastated Europe to such a degree that it could no longer afford to maintain it's colonies and assorted dominions. This, coupled with the wartime and post-war expansion of Soviet Communism in the third world, yadda, yadda, yadda. Certainly it's a fair point, but I think the argument relies on the inherent morality and lack thereof concerning colonialism in a modern age. How will British citizens feel being told by the government and social system that colonialism is inherently good or that the shift to independence is a good idea in the loosely long term but not now, and then seeing Nigerians executed and wartime atrocities broadcast on television? The contrast between the two in the same way the United States was receptive to the Vietnam War. I think the comparison is valid, because the United States never had much of a grand colonial empire -- certainly not in Vietnam. And even so, that war turned us off.
However, morality is not inevitability. Just because colonialism is wrong does not mean it was going to end. It will end when it no longer becomes feasible for whatever reason. And that is reliant upon economics more so than morality. When maintaining the empires costs more than it is profiting, and if profit even stops totally, that is when colonialism falls. That may come in the way of economic problems in Europe itself (WW2, as our OTL example), or it may come if rebellions and insurrections and revolutions become so problematic and expensive to fight that it's better to just drop the whole thing. And then you can say "It was morally wrong".
In terms of the actual post-war period, and the more minor war that was WW2 here, I don't know what happens.
Something I would also explore is federalization of the colonial empires. Britain considered it, but it was always a minority. Other colonial powers could consider it. The problem in terms of Britain is that federalizing the empire would have kept the empire, but the short sighted rebuke was that it would mean the colonies and dominions would be on par with parliament rather subservient to the White Anglo-Saxon parliament and the British nation. So now Britain has no empire nor any massive government that a federal empire would be. And the Commonwealth of Nations, while the closest thing to it, is simply a shadow of that idea. It doesn't really cut it. I don't know if you can overcome that, because as that example showed, the social force behind colonialism was inherently at odds with long term plans that would have allowed something resembling it to continue. Colonialism was never intended to be an empire of equals; that was the convenient lie. It was intended to be a small country maintaining dictatorship of other regions, and sapping them for economic gain, with the convenient self delusion that it was best for everyone.