Not an option, Sandman, I am afraid. Legally, Brexit happened in January. We are no longer members of the EU. The transition period end in December and any extension had to be requested by in June or July. In any case, from a UK perspective, the end of transition date is written in primary legislation and so it would need an act of Parliament to alter it.

Here is a clipping of David Davis from the Express in Jan 2019:
Brexiteer Mr Davis told BBC Today that the EU was "testing the mettle of the British Government. The government is running out the timetable, running out the clock but actually, there are now already signs that the EU knows it needs a deal and it will come back."

He continued: "The simple truth is that they will hold fast to their line - this is the traditional approach of the European Commission, the European Union.

"They will hold fast to their line to the last possible minute and then, if we hold fast to our line, then they will actually come back and renegotiate."

As far as I can see, the entire UK strategy has been what Game Theory refers to as 'Chicken'.   The claim is that all we have to do is stick to whatever we want firmly enough and the EU will concede in the last minute. We still seem to be playing the game today in what could be the last week for negotiations.

The problem, of course, is that if neither side gives up, you have an almighty head-on crash as both sides lose out. Which looks as if it is where we are heading. The sensible thing is to change course, obviously, but that is seen as losing, and neither player wants that.

There are a lot of mathematical Games in Game Theory. It is typical we took the highest risk one.