I've not done the maths but I reckon time spent at checkpoints will have more of an impact on your finish time than a small change in speed while moving. If you're able to grab what you need and go, especially on the night section when tired, you'll save a good chunk of time. Not messing about too much at Goring will help too, I took an hour there when I did it previously!
My plan is definitely to run as much as possible, minimal walking for the 1st 45 then walking as required from Goring, but hopefully not more than a couple of mins per mile avg.
I agree, rest it, not much benefit from more training now, maybe give it a v gentle 30 min outing mid next week just to warm it up, but no need for anything longer or quick.
Remember you've got 26 hours to complete this, 18 min miles will get it done. Essentially you could turn up and walk the whole thing (indeed, some people do), so take it nice and easy if you're not confident it's properly healed.
The race website has downloadable splits for the last few years, I used these to look at how people paced it before first doing it a couple of years ago. I think it was helpful. In the end I decided to ignore everybody at the start and try and run a fairly even pace but slow from the start. True to plan I watched everybody race off down the hill ahead of me and that's the most of anybody I saw for quite a while as I took a wrong turn an hour in and wasted a couple of miles! By halfway I'd started reeling people in then all through the 2nd half I was picking up places and finished about halfway down the field. Pace did slow but not massively and I was able to run all the way to the finish where many were resigned to walking 100%. I got pretty slack with checkpoints and after halfway made sure to sit down and have a cup of tea at each one. I think I probably spent more than 2 hours at checkpoints!
This time I'm aiming to get miles in the bank before the inevitable slow down and just hope I don't overcook it too early. Marathon pace at the moment I would guess is about 7:00, I'm looking to do the 1st half in 10:30 pace avg slowing to 12:00 for 2nd half. I don't know how well you know the course but there are some good hills in the first 20 miles so it's worth being more conservative so you can make the most of the flatter section after Chinnor and the downhill section from Nuffield. I'd say it's also worth being very brief at CP1 as you'll have a 5+ min walk coming out of Wendover to take some food in.
Another lesson I learned the hard way is with navigation. Don't be stubborn and assume you're on the right track if you're not sure of the route. The acorn signage is very good, so if you pass a set of signs and don't see mention of the ridgeway there is a good chance you've missed a turn. It's worth having a rough idea of the turns and terrain for each section so you're not questioning yourself or blindly going the wrong way - or actually follow a map!
Try to switch off eating for enjoyment and focus on eating as a necessity. In our day to day lives we pick nice things we want to eat and get a certain amount of pleasure from eating them. During long ultras you're lucky if you get the same pleasure from food so try to disassociate eating with pleasure and that might help you force down a couple of jelly babies you really don't fancy.
If you can pick something up at every check point and have a handful of something halfway inbetween then you'll have enough calories to finish. Worrying about numbers can cause anxiety and may sow the seeds for another excuse to get you to stop.
If you're having a real tough time then fresh fruit should get your through. Most aid stations will have bananas so take one with you and work on finishing it before you get to the next one.
A couple of years ago there were cold baked potatoes and an array of incredible looking homemade cakes at Sparsholt firs. It made me sad that I couldn't contemplate eating the cakes but the potato was awesome! If you can get potatos on the menu and smother them in salt then I'll be a happy/grateful camper. Coke always goes down well too.
Are you local to Sparsholt then Fido? Have probably seen you out and about if you are.