In theory, it is now set in law that the transition period cannot be extended. We've been told that if no progress is made by June, we will prepare for no trade deal and tariffs.
In practice, it's unlikely that either the UK or EU will be focusing on this, whilst this corona virus is doing the rounds. Key negotiators may have to self isolate or be unable to travel to trade talks.
Many businesses are likely to struggle due to Covid 19, and won't be in a great place to withstand any issues that arise from properly leaving the EU.
Before the Covid 19 crisis, Boris was committed to leaving at the year, whatever the cost. What will happen?