Battery tech is moving fast and could change before the vehicle life is up, other than the battery and body rusting, EVs should last a long time. I think a connector at the rear near the trailer hitch would be useful for towed extra power on the trailer. I think a fifth wheel equipped vehicle is for heavy often long hauling and an ICE truck might be best for that for awhile, until better batteries and charging infrastructure come along.
13 miles per hour on the internal 220 charger ain't bad and a typical night's charging could give you 130 to 150 miles of range to top up the battery, enough for day to day local driving and work for many folks.
I believe it'll hit its figures so long as conditions are ideal: single occupant holding to the speed limit, no load on hitch or in bed, nice flat highway in good weather.
I prefer knowing the range under the worst conditions for which the vehicle is honestly rated. 10 thousand pound trailer, four cornfed pax, half a ton of gear in the bed, rainstorm and big headwind going from Bakersfield to Mt Wilson. I would like THAT figure.
And the fullrecharge time at the campsite that only does 115 volts.At say 3.5 kW available, that's two days to get back 90 minutes of motion.
So far if the truck gets used as a truck, Diesel is the compelling option imo.
soooo sad! I missed the banter and the “dumb ass” label he threw out so sparingly ........ ok enough, I need a tissue 
