Hi PM, I was one of those near 60% unfortunately, through a bit of bad prep, bit of bad luck I missed out on a completion
But happy to get as far as I did and not do myself a mischief 
First off TDS is a beast, from doing 60m of UTMB last year I reckon that even without the weather effect it's a tougher course. UTMB huge climbs + 10% and quite a few rougher and more techincal paths. I've not slipped or fallen as much anywhere in the uk - but tiredness probably a factor here too.
Had rained most of the day, especially above 1700m. But then cleared up on the descent to Bourg St Maurice. Feeling the hills and miles here, but got stuck into the massive climb to Le passeur de Pralognan with somewhat renewed optimism, especially, nearing the end of the afternoon, we were clear of cloud nearing the top, almost no wind and sun came out. Got my soaking waterproof out of the bag and wore it as a cape for awhile to dry it out. Started to feel the wind again nearer the top and cloud and rain returned, so the almost dry 'cape' resumed its normal duty.
Passing over the top I realised where the wind and rain were, bashing into the steep face of the descent (roped in a few places to assist descending). I was in, waterpoof top , but otherwise very little protection on and didn't want to stop and lose my place in "queue" down. Unfortunately got stuck behind some very temntative descenders on steep, muddy scramble-rock climb down and got very cold.
Once I could finally pass and get going I tried to make haste downwards to get below rain (I hoped) or if not try and warm up a bit on route to next CP where I could warm up. I slipped off muddy path completly in my haste at one point and nearly down a bank. And rain and wind battered me till Cormet de Roselend where I arrive shaking like crazy.
Problem was everybody had stopped here because of weather, standing room only so I struggled to find a space to sit and get my kit out to change whilst still shaking. Took me ages to get two baselayers, waterproof top + bottoms and leggings, hat and gloves on and two soups + other food to get warm. Was still shaking after 45mins in tent and about to give up when it stopped. Glad I went on as near 500 people retired here!
I didn't get far though, over the next few climbs, but I was a shell. It seemed to get muddier and rockier on this section. Before my withdrawal at Col de Joly I was struggling to climb 100yards without my heart absolutley racing. And my descending, usually a strength was weak and clumsy resulting in stumbles. Retired through tiredness (physical and also sleepy - dropping off a bit - contributing to stumbles in areas where I couldn't afford to).