26 miles is roughly 2 to 2 1/2 hours commute time, which is up to 5 hours a day; and yeah, you'd need showers at the office.
I'll add a +1 for P90X, then. You could also dig into Insanity when P90X gets to be too routine. Last year, P90X -- plus watching what I ate -- helped get me into the best shape I've been in a long time. I have no intention of becoming a noodly-armed cycling specialist, though.