Oh and as for the British "Empire"... methinks it will go down the drain faster than in OTL. What is there that Britain can give to its former imperial cubs? Britain needs the dominions far more than the dominions need Britain. They need Australian grain, ores and uranium, they need Canadian grain and industrial produce. Canada on the other hand is rapidly growing its own industry, and its link with the USA will only become stronger.
Worse even, now that the war is over, Britain will have to pull even more of its troops and personnell out of the dominions to protect itself from the German threat.
South Africa is going to leave the Commonwealth very soon. (They did so in 1951 historically, with Germany ready and willing to take over as their partner, full of understanding for its policies towards the colored Untermenschen, it can happen even sooner.) India is set to leave the Commonwealth... Malaysia, Burma and Singapore are ready to do so as well, as soon that happens, inspired not just by India but also by the example of Vietnam. The question is, are the US interested in speeding up that process, or will they stop their liberation rhethoric?
I can't see Britain playing anywhere near the same role in this world as in real history. If Germany lets it be, then it might continue on a roughly historical trajectory (cautiously letting its Asian colonies go, trying to stop Arab nationalism and failing in the 1950's) . A difference might happen in the 1960's, when the African question becomes prominent. Historically, decolonialization in Africa was just as much caused by the unwillingness of the Euro nations to help their African subjects into the 20th century, as it was caused by the African will to become independent itself.
In a world where "bringing the Africans into the 20th century" is not seen as something that needs doing, and where Soviet support for African nationalists is a lot smaller that in history, then I don't see why Britain and France can't just keep holding on to their neglected colonies full of impoverished, illiterate, hunger-ridden Africans. World opinion might be a lot more tolerant... hell, barring a nuclear Armageddon, maybe even scummy little Portugal can keep working their salt mines and jungle farms with forced African labor well into the 21st century. Who cares.