It's all gone a bit pear-shaped

So we can't have the Chequers agreement because cherry-picking the single market for goods only  would undermine the EU single market for goods and services and, not unreasonably, the EU would object to its customs duties being collected by a non-member state.  (Would the UK allow another country to collect its customs duties?)

We can't have a Canada-style agreement because that would inevitably mean a hard border between Northern Ireland and the Irish Republic.

We can't have a Norway-style agreement because that would leave the UK as rule-takers, as well as paying handsomely for the privilege.

A "no-deal" agreement would be utterly disastrous for the economy and much else, especially because preparations have been totally inadequate.

Another referendum would subvert the democratic decision of the people last time around and, anyway, might produce much the same result.  Nor is it necessarily the case that a general election would resolve matters; even if Labour were elected (a big if), what would be their negotiating position.

And time is passing.  Tick-tock, tick-tock ...