Yes, the Halifax thread was good, also Tom Colton's Weber's Germany has a 1940 peace, though the POD is further back with different Nazi leadership.
Strategically and for long-term geopolitics I think negotiations (in equally bad faith on the British side to that of the Nazis - maximise advantages and prepare for round 2) could actually be quite good for Britain. It gains time for more re-armament and organisation of defences, and Germany can't enforce unacceptable conditions on Britain - the response to any attempt to do so is just 'OK, let's carry on then', and Britain is no worse off.
On the other hand, the short-term political fallout will be bad, probably leading to popular disapproval, loss of confidence in the government, perhaps a more isolationist USA. There will probably be a general election, perhaps a Labour government, which won't make much practical difference, as Atlee and his ministers will still be implacably anti-Nazi.
Added in edit:
Another factor is that Britain has quite big potential technical leads in some areas in 1940, though they probably don't realise it - radar, jet engines, even nuclear weapons, with the MAUD report. In some ways, all they have to do is build a bomb and a plane to deliver it, both available c. 1947.
The cessation of the U-boat campaign also probably helps Britain a lot more than the cessation of the blockade helps Germany.