I live in the north end of Seattle and commute downtown, so it's pretty easy to follow minor arterials which are laid out reasonably well. The challenge comes in the 3rd dimension; my round-trip commute is only about 15 miles but involves about 500' of total gain.
For me, cycle-commuting isn't primarily about love of bicycling so much as the need for exercise which is integrated into my day. I hate gyms and aerobic exercise machines, so bicycling is good activity and commuting fits it into my day. If I could kayak, snowshoe, or something like that for commuting I might try that.
I've managed to adjust to Seattle weather by purchasing 2 identical bike lights (NiteRider Trail Rat) -- that way I have a charger and battery both at home at the office, and rotate them so as to always have a fresh one available. Good, weatherproof lighting is important when it's dark and rainy, which is about half the year.