Nothing to contribute, except I had largely forgotten about riding in the Winter in England. The roads wet and filthy from September to April, the cold and damp getting into your bones. Looking like the creature from 50,000 fathoms when arriving at work.
Incidentally the best waterproofs I had (in the 70s) were made by Helly Hansen, it was a one piece, bright orange sailor suit, and was waterproof for hours on end at high cruising speeds in the pouring rain.
Best of luck!!