But working your strategy back from the "last" night? Really?
You have done this all before, Pete, as your subscription bears witness.
Perhaps what I was trying to say is: decide whether you plan to get a 'decent' sleep all five nights, including the fifth night. If you're only planning four nights 'sleep' stopping, then you can afford to be slower over the ground or stop at controls and enjoy being sociable, as you will not need to establish a 5 hour buffer for Thursday night.
I guess one approach is: set off and see how it goes. That's a strategy; of sorts.
You've suggested 'have a plan' and hope it lasts (eg to Edinburgh) and implied that 'events' will find you there with time in hand. This suggests that things are going well and you could sleep a bit longer on D3,4 and 5, indeed it suggests that the rider could have slept longer on the first two nights and kept closer to their plan. Perhaps they were not tired enough on that first night with an afternoon start, only 240 to Louth, the exhilaration of the start and the flatness of eastern England.
But another is to say, I'm setting out to complete in 110 hours (say - gives a healthy margin to the 116:40 deadline) and, based on experience/achieved speed on previous long rides (eg 300+), and a decision to get some sleep during part of each night, one will plan to stop (between 2300 and 0200) at a control and sleep. If you're planning NOT to sleep on the 'last night' (the 87% moon does not set till 0224) then your strategy can be different (less need for time in hand). But if you are then the allocated start time (and therefore completion time) narrows which control you need to plan to stop at (Spalding 180 to go, St Ives 120 to go). 1430 start requires a finish by 1050 Friday which gives about 6 hours of daylight (sunrise is 0525 at St Ives).
Personally my plan is to ride 310km (+ or - 10km) on the first 4 days in 17 hours including stops and allow 6 hours for each 'sleep' stop, aiming to complete by sunset on Thursday.
As you say:
fun to play with spreadsheets!