“so many propositions currently on the table from both the ex-Remainer and the ex-Leaver camps, to put it bluntly, delusional” policyscotland.gla.ac.uk/blog-sir-ivan-… - if you want to understand the state of Brexit and the UK debate, this by Ivan Rogers is the only thing you need to read
It is packed with killer quotes, and difficult truths for both Remainers and Leavers:
"There is no point in basing UK policy on fantasising about the EU agreeing something it won’t: whether on free movement, or on plenty else."
"There is no point in basing UK policy on fantasising about the EU agreeing something it won’t: whether on free movement, or on plenty else."
Personal favourites: 
On UK gov't's decision to rule out Norway and Swiss models: "Ruling out these options before truly understanding what either meant, or whether variants on them might be viable, was, in my view, simply an act of folly."
"All are wrong and are basically fantasist propositions"
"if we are to avoid miss-selling the British people on our post Brexit options, we need a far more honest debate based on clear, accurate, realistic accounts of the pros and cons of each of the options. Not on fantasies, or incoherent and muddled thinking" policyscotland.gla.ac.uk/blog-sir-ivan-…
"Which is why the threats to walk out have stopped and the repetitions of “no deal is better than a bad deal” have ceased." Brutal.
The section on the UK debate and Northern Ireland is particularly recommended: "It’s a debate which, candidly, bears very little relation to any debate the other side of the Channel, but be that as it may."
"The so-called maximum facilitation model will never be accepted by the 27 side of the table. Not now. Not in five years. Not in 105 years"
On the customs partnership, and the bizarre suggestion of having a backstop with a preemptively agreed end-date:
