iri's mileage
winter (-12 .. +5): cycle to work, go to shower room, don't shower, take off pants, take off fancy lycra stockings, take on pants, go to room.
summer (+6 .. +32): cycle to work, go to shower room, don't shower, take off riding t-shirt, possibly wash head, remove sweat with disposable towels, apply perfume, take on office t-shirt, go to room.
in seattle outdoor showers would be enough for me as well.