Scotland, though, has traditionally had more influence on the UK than mere numbers would suggest. Of course, that is less true under modern Tory governments who really are mainly English based (and mostly southern England at that, the current PM holding a Yorkshire seat notwithstanding)
Whatever happens though, nationalism there isn't going to die or even majorly decline any time soon - but an erosion of the recent SNP electoral hegemony is certainly more plausible, especially if a Labour government does take power in Westminster and is well received.
Quebec nationalism didn't so much die, but quietly evolved into an acceptance of Quebec as a distinct nation within Canada. The decades of uncertainty around Quebec's future also contributed to the stagnation of its economy relative to the rest of Canada, most famously marked by the exodus of the headquarters of the major banks to Toronto.
Of course, Britain's economy is stagnating relative to the rest of Europe post you-know-what, but a long and drawn-out period of uncertainty about Scotland's future can't be helpful to its economy, either.