For all we know, the EU could have already planned a no-deal scenario and getting ready for it.
You are right, that ball is worth about 40bn Euros. Long term probably even more considering future trades, goods and services: The EU could be losing access to a 65+ million people market; however the UK to a 450+ million people market. Personally, I would not be defiant but very careful - and I honestly think both side should be.
PS: Out of a crashed out Brexit, we ALL got so much to lose but very little to gain (if anything!). However - but i might be wrong - I feel Britain would loose the most: And to me it’s a rather sad prospect.