What she said. You are already daily commuting, so you are used to back-to-back-to-back in all kinds of weather days on a bike. Can extend you AM or PM commute to start building distance? Add hills to your route, and add what gear you'll be bringing to get used to the different miles, weight, and see if it affects your bike's handling. Work in some longer miles on weekends to fine-tune fit, equipment, etc. Have fun!