I'll vote for the Park'n'Pedal option. I've got a 43 mile each way commute currently and have been looking at options. I've got two Park'n'Ride lots within 15-18 miles from work so I'll probably pick the one with the nicer route.

Also keep an eye open for symptoms of over-training, exhaustion, crankiness due to fatigue. Would be a shame to loose your job due to a side effect of over-training.

Also, if you do crank out the whole distance, keep track of your hydration, especially once the warm weather hits.

And road hazards include critters which are especially active in the pre-dawn hours.

Have fun, be safe, and post some commute reports along the way.