Who needs flashlights?
If, as evidenced by Barbara in NotLD '90 one can walk up to zombies while in a wide open area, have a good cry while staring at one inches away, and completely control its movements with gentle prodding from a revolver barrel you're going to tell me Ben, Cooper or even that idiot Tommy couldn'tve done the same thing?

Night '90 is sort of a bad example, because the zombies were SO slow/non-reactive that a five year old with the sense to avoid the undead could've toddled away from them for some time.

That said, I completely understand the IMPULSE to want to stay inside the farmhouse. It's night, a time that people feel less confident/easy in their movements at ANY time, and everyone inside has been traumatized/had their world upended by the inarguable evidence that cannibal corpses were right that moment doing their best to get to and eat all of them alive. Combine those two factors and the decision to stay inside is understandable. Foolish, especially to remain on the ground floor when sabotaging that type of stairs could've been done in a 1/5th the time they put into barricading and re-barricading every entrance. Let the damned things get in! Who cares if two hundred of them mill around down on the ground floor and moan at you? You're safe as gold in Fort Knox in the unreachable upstairs, with the option to shimmy down the side of the house whenever you like the current dispersion of zombies at ground-level.

Look at the outside of the house as Barbara approaches it. There's a very solid-looking trellis along the side of the house nearly up to a 2nd story window, and a drainpipe that's somehow attached to a length of wood that's attached/raised up from the flat side of the house. Both provide relatively easy access to the ground, or you could even gather up all the sheets and tie one end around one leg of that huge hardwood 4-poster bed if you're looking for a 0% chance of sprain/miscellaneous ankle/knee/leg injury as you make your descent.

That, and as it turned out they could've just hung a sign from the 2nd story ala Dawn '04 and waited for the redneck cavalry to come save them. If they were smart they filled some containers with water before cutting themselves off from ground level and food isn't a concern for a 12-hour wait.

I also agree that you could pack at least 5 people into the cab of Ben's truck had they managed to refuel. Just have Barbara sit behind the seats, she's small enough. Then pile Judy on her boyfriend's lap in the passenger side seat and Mrs. Cooper on Cooper's lap squeezed in next to Bed who's driving. It would be cumbersome and awkwardly embarrassing to be reaching for the gearshift between Cooper's legs, but you can survive embarrassment when the alternative is getting eaten, blown up or shot to death. The dying/dead girl is the only one I couldn't find room inside for, but if the Coopers won't abandon her, or allow her to be placed in the bed of the truck, and even ride back there with her if they want, then to hell with them. Let them go hide in the basement and lock themselves in with their zombie daughter. Justice by any name...

I often wondered based on Barbara's ease of walking away, and Ben's successful movements after being tossed out of the truck, on the porch, and in general dodging and evading while Cooper made a power play to keep the door shut that if they'd have just taken the truck on fumes and used it to clear the immediate area early on especially, that it would've been even easier for all of them to walk to safety than it was for Barbara. I mean, it was obvious from the bodies and locations the rednecks were clearing that by no means were all the zombies for several miles in any direction focused on the farmhouse. Yes, they would've encountered one or a few from time to time, but the landscape was open enough to make escape via speed-walking laughably easy. Especially if they had all the guns at their disposal.

Finally, I agree that the setup of Fiddler Green security and its portrayal would turn any What-Ifs about Land into a multi-faceted security critique.