Ive ridden in cold wet, close to freezing. It is the worst combination and that time I used a cheap, yellow pvc non-breathable waterproof with a few wooly jumpers and some hiking boots.
Ive gone abit more hi-tech with paramo waterproofs, sealskins. Im not impressed with my featherweight pertex pants, my older heavier guage pertex was pretty waterproof for years. Im still old-school with gloves, woolen ones get wet but not cold.
The most interesting tech of recent times has to be nano-technology permanent waterproofing of leather. This was developed for the military and the first civillian hiking boots are showing up. It is not a membrane or surface treatment, it coveres every fibre and is really permanent. Just need a lightweight, slim boot without bulky padding.