For many, the belief that electrical vehicles being great for in city but for that 2% of the time when you need to go out of town and take long road trips, the EV world is just not there yet are still valid to some degree. It is also true that over the years of electric vehicle adoption there have been many concerns about range and charging availability but there have not been a lot of options out there other than just buying as big of a battery you can get for the vehicle and wait for the infrastructure to come into being.
That seems to be changing, at least in France and soon (2018) in North America, with an interesting take on range extension and the ability to turn your EV into a quasi-hybrid with the EP Tender.
The EP Tender is a tow behind electrical generator that provides power to your electric vehicle, but what is interesting is it is being marketed as a service rather than a purchase of the unit.
You simply rent the trailer for those long trips you want to take and cut down on the expense of actual ownership like maintenance and storage.
The electrical attachment is a direct DC connection through the trailer hitch and is a one handed operation according to the video of the product (below) and the generator claims to be able to power all makes and models of electric vehicles using its built in 100 liter fuel tank and giving up to 20 kW of peak charging power.
There is an interesting PDF data sheet on the unit here.
It looks like they are taking tenders on dealers in the North American market now and are starting up implementation shortly.