You don't seem to understand the impact a leading tory going against the leadership can have in Scotland. This could be a blip or it could be the start of the tories in Scotland seeing an opportunity to distance themselves from the 2.5 thatcherist parties in westminster once and for all and reclaim their historic place in scottish politics.
It would be progressive to see an non 'High-Tory' , non Thatcherite brand of Conservatism contributing to politics once more.
I don't think England will have to do anything but the Scots will have a lot of adjusting to do.
...so England will retain the UK seat in the UN Security Council in the next century? After a nationalist vote in Scotland, what remains of the "united" Kingdom is England plus what is left of English conquests of Celtic lands. Interestingly the Northern Irish part of that remains in the UK only because of settlement there by Scottish protestant loyalists- what happens to a loyalist in Ulster when the Crown stops being synonymous with England?
The defence of England becomes more problematic when the Atlantic and North Sea airspace and sea aspects are under the control of Ireland and Scotland - though membership of NATO by Scotland and some sort of cooperation of the armed forces would be likely as already happens with France.
If Scotland is not in the EU (as Cameron promises) then the Fisheries Agreement and rights to fish in Scottish waters goes away. The oil and gas from the North Sea will still be bought by England without getting the tax income. I guess England will perforce get more unpleasant 'fracking' of shale gas and will still be buying a lot of energy from Scotland's excess of hydro and natural resources as well as gas and oil.
It's not all one sided.
The tories in Scotland were pretty strong and got plenty of votes before Thatcher. Conservatism without an attchment to the Westminster party could resurge in an independent Scotland.
The right in Scotland is hampered by association with the English Tory party and Scottish Conservatives would probably be restored to the sort of vote they had before Thatcher. Though the complete collapse in Conservative votes came in stages for the last 80 years.
In the '50s there were around 30 conservative MPs in Scotland, in the '70s it went down to 20, in the '90s to 10, and now zero. So Thatcher and her experiments with poll tax on Scots was an element in the decline but possibly more of a nail in the coffin.
Labour have varied between 40 and 50 MPs since the '80s. The Libs/Lib-dems have gradually come up from 5 to 11 MPs over the same period (and their lies about university charges don't affect Scotland)
I reckon the Liberals and Conservatives in Scotland are genuinely different beasts from their English counterparts and they have a chance of resurgence in an independent Scotland. The SNP will be a bit of a force to reckon with but their raison d'etre will fade in the next decade and Labour holds the loyalty of a huge percentage of the population, so the mix will probably settle back to a Labour majority leading to a 21st century of generally Social Democratic government in Scotland not unlike most of northern Europe. With England being a more right wing place as they continue to handle the disappearance of the last privileges of Empire.