[that] "the EU would be only too happy to retain N. Ireland within the CU and Single Market"
is exaggerated.

The document published this morning and subsequent statements by Barnier do suggest a "special" status for NI.

Guiding Principles for the dialogue on Ireland/Northern Ireland

They also indicate that it is up to the UK to come up with a workable solution and that that solution will not form the basis for the future relationship between the whole of the UK and the EU.

The  onus  to  propose solutions  which  overcome  the  challenges  created  on  the  island  of  Ireland .... and the internal market remains on the United Kingdom.