Maybe it is time to rip up the EU agenda and start again from scratch? There is no doubt that mistakes were made over the years and maybe, just maybe, the UK electorate might respond more positively to a reset of controls and powers?
I think this is the great failure of cameron. He danced around it in his letter of demands, where he had the perfect oppotunity to set a stomr off but failed to demand full political accountability from the EU appartus to the people in exchange for campaigning for remain. This and exemption from ever closer union would likely draw a lot of support from other eu member states and UKIP voters. As well as frame the debate as sovereignty or brexit rather than immigration and trade (while still benefitiing) it's also blizzare the negotiators never approached Switzerland Or the eea since a good deal might be good for them too. A multiple block would have more power over eu.
A two tier eu perhaps with a revised eea which still allows outside trading might not be a bad idea. Most of the objections to two tier is from countries like Poland who don't want to be in the 2nd tier, they may well be fine with the UK in the 2nd.
Hell throw them a bone with a defence pact, why not let the UK security council seat be EU? It would hardly make any difference to anyone in the UK, and would give the military more soft power through an appropriate eu UK treaty.