I don't think this is a possible TL if your are going to have English existing at all in the small area. This isn't due to history but the nature of English.
Most linguists admit that English has a major advantage over the rest of the world's languages. (All of the world's 'great' languages have such advantages, but in English those advantages contribute to its spread more than most others. )
English borrows words with a greater facility than almost any other language. This gives it a greater vocabulary (500,000+ words vs 300,000+ in its closest competitor) and thus a much wider range of expression with words alone. (It also leads to its greatest disadvantage, pronounciation and spelling, these are both very difficult in English as it very often does not follow its own rules). In addition, it was from the beginning a 'developed' language with its characteristic simple structure. These two facilities make it not only easier to learn but also a natural for the 'pidgin' process. Examine the world over and you will find wherever languages naturally mix to form others, pidgins, that English becomes the base and structure if it is one of the components.
If you place your POD after Britain had developed even a few colonies then the genie is out of the bottle. English may spread less but it will still spread widely. If you place it before that then whatever form of English was here already simply gobbles the new language into itself and then is spread by the conquerors. You may end up with a world where English is less widely spoken or sounds rather different but I do not believe you can end up with a world where some form of English that we would recognize is not spoken on a global scale.