I just rode a grainer from St. Louis to Springfield last night. My tent stowed nicely against one of the sidewalls of the porch, concealed well from sight, 2 of my backpacks and sleeping bag all strapped together rode in between the V walls, and I rode in the doghouse with my smallest pack. Not super comfortable, but riding a grainer isn't comfortable even if you're packed light imo.
And even though I'd rather not if possible, I caught on the fly with all that crap last night.