Just connect one of the diesel pumps right into the diesel generator

No one is buying diesel cars now, or so I hear.
The biggest issue with charging on the go happen on the busy days, like long weekends or when escaping natural disasters (hurricanes, wild fires etc.).
Tesla drivers have reported waiting 4+ hours at superchargers in their SFO-LA trips. It is quite likely, as all of them go and come back around the same time. Many car waiting lines are a common sight in Palo Alto superchargers. Recently, Tesloop also ended its services because of charging issues. These, even when Tesla is in full control of all its chargers. Lots of stories here. Not good to be stuck there for hours with tired kids and family in the tow. The family may just bid goodbye.
https://teslamotorsclub.com/tmc/threads/superchargers-super-slow.81432/
45 min charge becomes 4 hour nightmare:
https://www.reddit.com/r/cars/comments/821zzc/mountain_view_california_tesla_supercharger/
https://www.wheels24.co.za/News/Gea...-to-have-their-electric-cars-charged-20180305
IEV itself:
https://insideevs.com/tesla-owners-report-waiting-hours-open-supercharger-wvideo/
Even fights reported at supercharger to get a spot. Mnd you, these are presumably pretty well heeled customers and this happened two years ago. Once the low lives start driving EVs, no telling what it's going to be.
https://teslamotorsclub.com/tmc/threads/rage-at-a-supercharger-station.66722/
These are stories before the Model 3 wave began. I can't imagine this getting better. Here is one posted on reddit just today, for 7.15 a.m. at San Diego.
https://www.reddit.com/r/teslamotors/comments/9k6rge/715am_at_the_san_diego_qualcomm_supercharger/
Tesla has also been putting up diesel generators to cope with the extra load. A PHEV is more efficient than that and can do so while driving. You can think of yourself as letting some other BEV driver get a charge, meaning you are helping the environment anyway and also saving yourself the time and trouble
In short, I think full electric cars really need people to bend their lives around the charging issues.