It's fairly clear at this point that the EU has no intention of doing a sensible deal for the British. They are driven by the wish to protect the EU organism, the Empire bug which has existed for millenia, which means their position is that the UK must be worse off for leaving.
The British, like the confederacy, see no reason why they shouldn't exit a club of which they don't wish to be a member. Unlike the US, the EU isn't a country yet. So it can make no claim of indivisibility, in spite of having no exit model.
The British people voted to get their sovereignty back. If that does some damage to the UK, the choice to avoid that was on the table when the vote was had. The government's job is to honour the desire for sovereignty of our nation and to minimise the damage.
I think we are going to end up with a minimal contract or no contract at all with the EU. The World Trade Organisation defines trading rules between countries that have no treaty. It looks to me like that is where we are headed.
Punishment is dumb, but it's fixed in the EU's stance. Time to get some new treaties with partners who respect our independence.
Maybe a common law area. Or a shared-monarch, independent-sovereignty, trading territory, which is my ideal: what we should have done originally instead of Anglocentric mercantillism.
The WTO tariff model would serve as a bridge to non-members. Such as the EU.