"The thinking is that a delay would not solve the fundamental policy problems and that a deal is either possible or not."

There is something in this. Have thought for a while that COVID poses much bigger problems for implementing Brexit than it does for negotiating it. https://twitter.com/SpecCoffeeHouse/status/1250385973181067266

And if the real issue is implementation rather than negotiation, that raises the question of whether extending the transition period - which is really a negotiation period - is the best tool to address the problems caused by COVID.

Much better to bake a new implementation period into a deal.

Ideally you'd construct it so that you have such a grace period for a No Deal scenario too, though that might be hard to agree

There are also things the Government could do to make the implementation side of things easier in new context. What about reconsidering the wisdom of introducing full new import controls from day 1 (a new policy, as explained in this thread)? https://twitter.com/DomWalsh13/status/1227009275387662337