Yeah car
Yeah car needs to be on! Check, thanks!!1500 is enough to run a 75a dc charger for the camper batteries. It's also enough for a coffee maker, microwave, and wired chain saw.
1500 is the sweet spot. Most corded items can be run. But in the highlander I think it requires the vehicle to be on. I might be wrong.
For that reason it's probably ideal to consider what you could use for shorter durations. Microwaves and coffee makers come to mind.
You could run an ac unit... But I wouldn't want to idle my car for 8 hours.