Right now, mine is just a puddle-jumping, 10 mile round trip.
Takes about 15 minutes going to work, and 20-30 going home due to hill stack-age.
I don't even go fast, usually averaging between 10 and 30 mph both ways.
Luckily, the commute route is East and West, so the only thing I have to worry about are crosswinds.
And the MTB I'm riding isn't much of a speed demon itself either.
With that and a 20 lb backpack, the speeds I make are killer.
Now my mind is just getting out of this area I'm living in.
With these constant low-pressure systems hovering over SoCal, the Mojave Desert is like the freaking "Great Plains" of California.

Oh, and before you commute, watch or punch up the Weather Channel.