My commute is about 22 miles one way. It is to college. I bike commute when I feel like it, other days I car pool. I just started recently though.
I have ridden my route one way, but not both ways in a day before. Tomorrow will be my first 44 mile day.
The route is mostly back roads with light traffic, no shoulder, decent hills. I have a few hectic city areas I have to ride through, but that's alright, it keeps me on my toes.
I travel light. I know the day before I am going so i leave a notebook/text in a locker at school. I also deposit my kryptonite lock (u and cable) in the locker so I don't need to carry it. I typically only carry tools and layers. And hydration of course.