For what it's worth, I wear an old pair of Billabong cord shorts (3/4 length) with
Decathlon padded shorts underneath (I do an 8 mile each way commute). The cords are nice and warm (but being 3/4 length not too much so) and the only thing I'd change about them is to give them pockets with zip closures (atm everything I might need goes in jersey pockets).
Cord seems not to lose much heat in the rain (although I ride on drop bars, and I think my riding position keeps a fair bit of rain off my lower half).
I guess the only problem would be that cords would make you look like a geography teacher (wonder if I can get a hi-viz tweed jacket, with reflective elbow patches...?)
I've tried a few baggy shorts etc with inserts, and not really liked them (the ones where the inserts are attached never seem to get the fit of insert and trouser/short right, and the ones with separate inners, you might as well just wear bike shorts under another pair of shorts/trews)