I’ve got some Berghaus waterproof cycling trousers and I’ve often wondered why more people don’t use similar. I have a similar length commute and arrive dry and comfortable. I wear thin Ron hills under them and in worst of the winter will wear thicker Ron’s.
I wear them off road as well.
I did get a pair of weatherproof Singletrack trousers but sent them back as seemed the worst of all worlds. In cold I wear shorts with Gore leg warmers, in foul wet I wear waterproofs.
Seems a no brainer to me. it is immensely satisfying riding in foul weather but still being comfortable and dry.