We did 10 weeks from East Coast to West Coast, hitting many of the National Parks while on our trip.
While we had electric everywhere we had planned to stay for everything longer than a night, we wanted to be prepped for any possible overnights if we needed to stop at a Walmart lot, rest area etc... A Honda 3000UI was purchased prior to our trip and was secured in the bed of my truck in case it was needed.
The other thought was what if we lost power in a campground? That has happened to us before so we took no chances... This to me was like an insurance policy, there if you need it but OK if it is not used!