I personally don't think we need a POD as far back as 1066 to achieve this. All what we need is an England which during the age of nationalism espouses a staunchly 'Anglo-Saxon' nationalist variety that solidly looks back to Anglo-Saxon England pre-1066. This ATL nationalism would be largely based on OTL thought, such as that of the 'Norman Yoke' and the Whiggish interpretation of history, which stated that Anglo-Saxon England was a kind of Garden-of-Eden liberal constitutional monarchy in which the Witangemot was England's first parliament, and that the Normans destroyed all that by imposing a foreign autocracy.
So what we need is an ATL English nationalism that emerges, say, in the long eighteenth century after the revolution of 1688 that is a reaction against French-backed Catholicism and Absolute Monarchy and could see Dutch support for that revolution and William of Orange as a sign of pan-Germanic (and Protestant) solidarity. This Anglo-Saxon revival, for it to permanently confirm England's place in the 'Germanic Club' would have to last continuously during the Eighteenth and Nineteenth Centuries. In addition to changing/ requiring a change of England's self image, literature and politics, I imagine that the following changes would be noticeable:
- The mass re-adoption of Anglo-Saxon first names in England during such a period: Names such as William, Henry and George go into decline and normal English names become names like: Athelstan, Edgar, Elfgar for boys and Godgifu, Elfgifu for girls. Scandinavian names (very popular just before 1066) could also become the English norm, such as Sveyn and Bjorn, which would further 're-scandinavianise' England.
- Indigenous English roots being used for new words that enter the language rather than importing Greek and Latin for say, modern concepts and technologies.
- The use of Anglo-Saxon words for newly created political institutions - so that when, for example, the American Revolutionaries were creating their constitution, instead of using the word Senate, they use the Anglo-Saxon word 'Witan' to refer to their upper house. Likewise when County Councils are created in England in 1889, have them be called 'Shire Moots' instead.