I thought about this a bit more. My two main commuting revelations have been waterproof shoes and jeans with a gushet in the crotch.
It took me far too long to even think about looking for waterproof shoes, but what a difference it makes not having to worry about cold wet feet once I get to work. Still looking for a pair with a sole which doesn't wear through in six months, but I may just need to spend a bit more money on them.
I own two pairs of these jeans: https://www.betabrand.com/bike-to-work-britches.html Whilst the reflective details are nice, it's the gushet neuk in the crotch which makes them worth the money. I believe other manufacturers sell similar jeans which also have a water-resistant coating, but I'm hesitant to believe it lasts long enough to be worth it.