It's not a very interesting concept if it's limited to one place and time. I think you can abstract a lot of the features of the languages originally classified as creoles and apply them where-ever they make sense.
Personally I would say that Modern English is not a creole, and Old English is not a creole, but there was certainly a period of time in the early middle english period were England was invaded by the Norse and Normans that a lot of creole-like changes happened to the english language -- particularly the loss of grammatical gender and many declensions and conjugations and a simplification of grammar, and it happened for similar reasons -- an upper strata of society that spoke a different language being forced to communicate with the local people. And English at the time was definitely not considered an important language worth studying and people very rarely bothered even writing any books in English. I think it's worth thinking about the similarities and difference between what happened to english in the early middle english period, and other "true" creole languages beyond just saying it's not creole because it didn't happen in the 18th century.
Personally I would say that Modern English is not a creole, and Old English is not a creole, but there was certainly a period of time in the early middle english period were England was invaded by the Norse and Normans that a lot of creole-like changes happened to the english language -- particularly the loss of grammatical gender and many declensions and conjugations and a simplification of grammar, and it happened for similar reasons -- an upper strata of society that spoke a different language being forced to communicate with the local people. And English at the time was definitely not considered an important language worth studying and people very rarely bothered even writing any books in English. I think it's worth thinking about the similarities and difference between what happened to english in the early middle english period, and other "true" creole languages beyond just saying it's not creole because it didn't happen in the 18th century.