It's worth considering what the UK's other EEA trade partners are doing to prepare for Brexit. Today, a report from France, which reflects the EU's belief that it's best to assume No Deal and be pleasantly surprised.
Of course, it would be easiest for them to switch any existing English law agreements to Irish law and courts to minimise disruption ;-)
In a document given to business owners, the Ministry of Economy and Finance reminded them that in all cases the United Kingdom will become a third country from 30 March 2019. The document advises that French businesses carry out a three-step self-diagnosis in order to prepare. This consists of analysing the consequences of Brexit on their business, identifying measures to be taken and preparing with their subcontractors in advance. Finally, the document urges them to implement these measures as soon as possible.