What options are Open to Boris Now?

After the catastrophic legal failure yesterday, Boris has really got to pull something out of the bag as the remainer walls close in on him.

He now has to abide by the Benn act, he cannot trigger a general election and get support, he cannot stop Parliament from sitting and tying his hands further.

He could use the executive powers introduced by Tony Blair, but he will risk another intervention from the Supreme Court as they have now established themselves as the ultimate arbiter of government policy.

I think the only avenue to the PM is to follow the instructions from Parliament: he WILL ask for an Extension and WILL accept any extension given, as ordered by Parliament. BUT he doesn't have to offer anything in return: I expect he will say there will be no further payments to the EU.
The EU may then refuse an extension, or allow gratis open-ended continual membership of the EU while negotiations take place.

It's then up to the EU to decide if the allow us free access to their markets and political machinery.