Personally, I'd just keep watch on the weather forecast (and the hotel's cancellation policy), and if all looks okay, go for it! 53 miles on a bike is really not that far, especially if the terrain is similar to what you're used to riding.

The good thing about university people is that they're usually too out of it to notice what you're wearing, much less if it's wrinkled. Even if it were a work trip, you could probably get away with shoving a suit in a bag and then letting the wrinkles come out overnight in the hotel.

It sounds like the point of this isn't to save money - it's to experience the feeling of being able to transport yourself somewhere by bike. The convention is just a really good excuse to try out some new roads and see what happens.