I have the teardrop toolbox on my Softail. I have enough in there to get the seat off to access the battery and fuses and get a wheel off if needed.
Never needed any of it though.
That's nice the seat off. I took the seat off in the garage to hook up a battery tender well it took 5 minutes to get it off and an hour and many words getting it back on. I was hoping to never have to take that off again.
I have a teardrop toolbox. I keep a Leatherman multi tool, small LED flashlight, a few Allen wrenches, Philips screwdriver, spare fuses, folding knife, small flathead screwdriver, 10mm combo wrench, and a few other tools I can't think of right now. I also carry a roll of duct tape in my bag. If I have a major breakdown, I have my cell and credit card, but for minor things, I can generally take care of it myself.