I use a dill pickle handlebar bag and it's much smaller than the traditional boxy type. It holds enough stuff for me on 200/300k rides and is nicely supplemented with a medium or large saddlebag on longer rides. It's nice to leave the big bags at home on a supported 600 with a good forecast.
I haven't tried a traditional rando rig so I can't really offer an opinion but I dunno where you'd get one off the shelf in time for Christmas this year.
I think if I upgraded I'd get a fuji jari or trek domane since they can handle fenders and wide tires. I've been thinking about a low trail bike but really don't know what I'm missing.