As someone else said, this is my worst nightmare. Nothing is foolproof, but I check everything I can everytime I head out. Fluids, belts, hoses, fuel connections, brakes, tires, etc.
Last year at the end of our annual Columbus Day trip I had the semi-nightmare scenario. Semi-nightmare because it wasn't roadside, but I was stranded far from home. I'm a weekend warrior so I need to get back home Sunday evenings and to work Monday morning.
I was at a state park with no cell reception. I pulled the motorhome forward and off the leveling ramps so I could dump the tanks. Dump done, ready to go home I cranked it and it wouldn't start. The battery was already questionable (yeah it was on the to-do list) so it cranked dead pretty much immediately.
I had a battery charger with me so I plugged it in and let it charge while I contemplated my next move. My brother-in-law was packed up and hooked up to his trailer and almost left. I asked him to hang out because I may need a ride to an auto parts store (wherever that might be).
For an internal combustion to run you need fuel, air and fire. I pulled a plug wire and cranked it - I had no fire. The ignition modules on my particular engine were notorious for failing unexpectedly. I had a spare, but in an "it won't happen to me" moment, I left it home. In my mind I could see it in a box, on a shelf in the garage which didn't do me any good at all.
My bro-in-law drove me to the closest auto parts store - about a 30-minute drive. They happened to have the part in stock. I swapped it out and it fired right up.
So all in all it could have been worse. I was stranded at a campsite that I technically had to vacate. But given the extenuating circumstances I'm sure I could have camped another night if need be.
I now sacrifice a bit of storage space for a spare ignition coil.