The truck has ~$1k worth of emissions scrubbers in its exhaust, maybe more. You're not going to beat that performance with a portable generator. The Honda generator doesn't even have a catalytic converter.
Yeah, but the scrubbers don’t help CO2, which is the most important pollutant these days.
The hybrid truck could run an inverter off battery (in theory), and cycle the engine on and off. A dirt cheap generator (Predator 8750 from harbor freight) runs 8–12 hours on ~5 gallons (the spec sheet doesn’t give tank capacity)
How many gallons per hour does an idle truck burn?
Honda portable generators are some kind of magic. 90% of that thing must be a muffler, but I've never seen a tear-down. I knew a bunch of people into flying model airplanes, and every single person would have one of these out at the field. Until someone pointed one out to me, I had no idea 5+ generators were actively running around me.