will probably depend on a number of factors including wind ,# of riders, traffic lights etc etc. Sounds like you are prepared to cover the distance and I would suggest not being concerned too much about the time. Unless you have timed yourself on this particular route it will be tough to guage anyways. I've found riding in these events it is best to just go with the flow and stay out of trouble as you will see all levels of riders and if you find some open road then go for it.