on the topic of backup plans:

having only a small window for taking a bus home (4:00 - 5:30pm), and being 40+ miles away from home initially was a concern for me. over time though i've become very good at managing my time. i have no problem dropping my work when it's time to run and catch a bus. additionally my coworkers know i need at least 1 day's notice before scheduling late afternoon meetings lest i'm fuc't. missing the last bus means a 3 hour ride home, and in some circumstances (i.e. leaving after 7pm) it's just not viable at all.

for the OP: if you're worried about the backup plan, don't be. worst case scenario you can catch an expensive cab ride home if you really need to. but in 3 years of bike commuting long distances, i've never once had to rush home for an emergency.