works for me!
The existing performance values for the box truck could be converted to electric-equivalents and allow insights into motor/battery requirements for a given speed/range target.
Electric motors have the equivalent of around 0.15 lb/bhp BSFC where a diesel might be on the order of 0.40.(we'd want to do the homework)
We know NASA got Cd0.238 out of their 'Shoebox' project,and we could improve on what they did.
Regen would really be a game-changer in an RV.They have such a huge penalty in stop-and go,which a BEV could take advantage of.
Downhill regen instead of braking.
As Volkswagen gets their 1,000, fast charging 'Electrify America' stations installed,that opens up even more options for BEV RVs.
If you don't do it,I suspect it won't be long before someone else does.