I know that I put too much in my bag drops which led to a lot of faffing and deciding what to take or leave.
I left -sun cream , warm gilet, thick waterproof gloves , spare jersey and camera. I almost regretted leaving the warm gilet, a Rohan Icepack, but on balance ,the majority of the control buildings were warm enough.
I dumped a lot of gear at Barnard Castle and despite the weather, I was never cold, due, I think, to having a decent jacket-Montane Stormrider , a Sealskins semi waterproof cap and thin woollen liner gloves (worn as normal gloves at night).
I had experienced similar conditions two weeks earlier on the Border Raid 600 and I live oop north.YMMV.
The gear that I carried in my saddlebag was all used quite often and meant that my sleep stops weren't tied to bag drops.
Silk sleeping bag liner, merino base layer and merino skull cap (kept dry for sleeping in) , wash kit(tooth brush and paste,shower gel, mouth wash, arse cream etc.), three quarter length shorts for night time riding, dry socks (as well as 2 inner tubes, multitool, levers , pump etc).