I find that I sweat in whatever raingear I wear, even in cold temperatures.

I've experimented a couple of times with simply layering up on the wool, and will give it a go this season. Thin merino base layer, thick wool sweater over....

Of course, my commute isn't as long as yours, so less exposure.

On touring days where I've ridden in the rain all day I wore rain gear, still got wet underneath after hours and hours in the rain. The wool under helped me to stay warm even when wet.