In the dark ages, many of the ancient Britons left the country, so Brittany, where they went, became Little Britain and this island was Great Britian. It meant bigger rather than better. If you want it to be bigger again, I suppose reconquering India and the USA would be a start.
I think we should start small scale by putting the Great back into Great Snoring. If that works, simply expand the strategy to cover the rest of Britain.