Could this keep the UK united and in the EU?

[AuH2O Republican]

Although I like this plan as it would essentially give the whole of the UK a vote on whether Scotland should secede or not, I can't see it happening. The SNP obviously value a union with Europe more than with the rest of the UK, so why take a chance on the UK voting on a 2nd referendum over EU membership? If the UK says "fine, we'll stay in the EU to keep our own union intact" then Scottish independence is doomed.