I did a calculation with the Brexit vote a little while ago, not that the issue is important for the information I was looking for. I discovered that if England had voted 59% for one outcome, Scotland, Wales and Northern Ireland could all have voted 100% for the other outcome and lost. That means that, in a referendum, if England wants something enough, there's nothing the rest of us can do.

I also remember Feedback mentioning once that if you combined the seats won in Scotland, Wales and Northern Ireland, they have never made any difference to the result in a general election.

Democracy.