Thanks for the replies, I really appreciate it. I'm not going to be carrying much with me but will be bringing a suit, shirt, dress shoes, etc. I know all of this fits in my briefcase so am good there and can use my briefcase as a briefcase when I arrive. Also, my bike ride is only 4.5 miles each way and 3.5 of that is on a paved bike trail with the final mile being up a city street. I think I'll go ahead and get one of these wooden crates built:

wooden bicycle crate made in Brooklyn from reclaimed NY wood

Just wish there was a way to create a quick release for it so I could remove it easily if need be but doubt there is. Thanks again everybody.