As an ex-RAF pilot I still had to do my initial Class 1 at CAA Gatwick as my SMO was not a CAA-ratified AME. If yours isn't, you'll have to go to Gatwick too - unless things have changed since I left.
What esle can you do? I assume you intend to take the modular route? In which case, you can select and sign up with a distance-learning ground school provider while you are OOA. That'll keep you quite busy enough. Read and inwardly digest the Archive thread at the top of the forum for more essential info.
Scroggs