Shimano Storm Jacket. It has a vent cape in back but I've been intending to have a tailor add some metal mesh grommets to the underarms. Otherwise I need to unzip the collar a bit to get some ventilation to make the vented cape effective. It's a seriously effective storm jacket, with double sleeves and all kinds of extra bits to snug or loosen as needed, depending on wind and rain. The inner mesh liner helps reduce sweaty shirts sticking to the shell. Detachable hood, fits in a jacket pocket.
Long sleeve Champion thin poly t-shirt. Nike Dri-Fit hoodie or comparable top between the undershirt and jacket.
Women's generic fleece tights (cost around $5 apiece or so from Walgreens). The material feels nearly identical to cycling apparel. Jeans, or shorts and knee warmers over the tights.
Thick microfiber knee high socks. Merrell shoes, which are nearly waterproof, and waterproof shoe covers.
Poly or silk ski glove liners under Bontrager RXL Thermal gloves, or generic ski gloves if it's cold enough.
That's what I did wear last year for cold wet rides. Even when some material soaked through it was still reasonably warm.
If it might rain, I may just take an ultra thin Pearl Izumi Elite Barrier jacket. It's just a windbreaker (no hood -- that's what the Nike Dri-Fit hoodie is for), only moderately resistant to light mist. Packs into its own rear pocket, fits in a jersey or handlebar bag, or some larger saddle bags. But when I've been caught in the rain with temps in the 40s it was tolerable as long as I was dressed properly underneath (same stuff described above). The wind resistant shell reduces wind chill, even after soaking through. But my longest ride in that was around 12-15 miles home, temp in the lower 40s with rain.