I'm sorry, time to wake up from fantasyland of sovereignity. Decisions have consequences and it was rather obvious that the incentives become rather misaligned when UK decides to tell EU to go fuck itself.
UK did enough damage already, the latest and most glorious example is blocking finance reform so you could protect your criminal banker city (which, ironically will probably pack up and leave after brexit)
EU has no obligation to make special concessions, quite the contrary - it is obvious you cannot get a better deal than for example Norway, nor can you continue to benefit from common market without agreeing to it's most core terms
Sure, the Euro is in dire need of remaking, maybe explosive collapse of UK will be glorious enough to force some changes in that regard, so...thanks!
I absolutely understand that the EU can simply "refuse to play" and that's what I expect them to do. See my comments elsewhere. The EU is held together by fear and needs to make itself a sworn enemy of any country that wants to get out. It's an unstable strategy and it will eventually cause serious chaos, especially when the Euro falls apart. If the EU was willing to undergo massive reform and change itself, the transition could be orderly and yield minimal or even positive economic impact. It never will, so Europe is gonna have a very troubled next few decades.