Another vote for rolling. That's what I do with my pants and shirt.

I iron the shirt the night before and let it and the trousers stay on regular hangers overnight. In the morning when I get up, I roll both. For the shirt, just take some time make sure that the 4 panels of the short are laid out flat and wrinkle free before you start rolling. By the "4 panels", I mean the fronts from the side seams and the 2 panels that the back turns into. Neatly fold the arms over onto 1 side. Start rolling at the bottom because that will wrinkle, but the tails get tucked in anyway.

I've got a 30-35 minute ride, so the shirt is in the backpack for an hour or so. I pull the pants/shirt out when I get to the fitness center where I shower and hang them up. It takes me a few minutes to cool down before I can shower, but by the time I'm out of the shower, any "ride wrinkles" are pretty much gone.

I use a backpack. I've thought about getting a rear rack and garment bag, but I'm not convinced that clothes will stay dry in a garment bag.