How far? The guiding rule should be the principle of "subsidiarity" - "Subsidiarity is an organising principle of decentralisation, stating that a matter ought to be handled by the smallest, lowest, or least centralised authority capable of addressing that matter effectively. "

The Westminster government as it stands is close to the opposite pole. Mind, so would be an independant Scottish government in Edinburgh. It's a long way to the Shetlands or the Western Isles, geographically and in all kinds of other ways.