Electric powered vans may be useful for a business where they work within a small radius and return to the depot regularly where they can be recharged.
In the case of the Cali which will be covering long distances the batteries will become exhausted and the vehicle will then have to switch over to an alternative source of power or stop to recharge; the latter option being impractical with the present number of recharging points. My wife has a hybrid Golf and we already have been unable to recharge due to the growing number of PHEV's queuing to use the plug ins.
Our journeys in the Golf are generally short, and for our use it works very well. When the batteries are fully charged the indicated range is (optimistically) shown as 31 miles, so on shopping trips and visiting local relatives it is very cheap to run (and pleasant to drive).
Now, the weather is not too warm at present so let's put the heater on. Guess where does the heat comes from? Yes, the batteries. Switch the heater on and 6 miles disappear off the range straight away! You can warm the car up prior to setting off while it's still plugged in, but that doesn't last long and the windows soon start to mist up. So you can open them and freeze, or just let the ICE (internal combustion engine) come on a bit earlier. Once the engine comes on petrol consumption is no better than conventional vehicles so journeys beyond 25 - 30 miles will cost the same as now.
So by the time the T7 appears maybe there will be a full electric version (like Nissan etc have already) but it will only be suitable for a local delivery van. For longer journeys it would need to be a hybrid, so there will be the weight of the batteries and electric motor, plus the weight of the ICE and gearbox etc. The Cali already has a slim payload so unless some major slimming of the caravan components takes place we'll only be able to carry a couple of cans of beans with us!
Also, the current Cali is pushing £60k with a few options, so by the time the T7 appears we could be looking around £80 - 100k with the extra cost of the hybrid gear. And it will be unlikely you will be able to recharge on the camp site as the current draw from the charge will likely trip the supply!
I'm not anti electric cars, I think they are great, but I just can't see the Cali being suitable. I don't see the current incentives for going electric being sustained either.