The conclusion: nothing is certain, and there must be a future path back to a non-Tory government. This will involve luck, but also a decent amount of design.
Two main obstacles block that path.
First: the “Scottish problem”. The last Labour government held 41 Scottish seats; today the party has one. The SNP’s rise has helped the Tories in two ways. Tory opposition to independence detoxifies them for “unionists”; and more importantly, the SNP’s strength in Scotland blocks a UK Labour majority. The Tory trump card is that the only alternative to a Conservative majority is a ragtag Labour-led coalition, with the nationalist tail wagging the dog and demanding the dismantling of the UK.
And why should the English be ruled by the Scots?
Independence now therefore.