The combination of towing range and the time to recharge is important. What good would a 200-mile range be if you had to charge for 12 hours first? But if you could get a 100 mile range out of a 15 to 30 minute charge, that wouldn't be so bad as long as there are a lot of readily available charging stations.
I always wondered why no one has come up with an electric powered trailer that could possibly be used as a range extender as well. The hardest time an EV has towing is going up a hill. If the trailer could assist, that would really help the range. And you could have the entire roof of the trailer covered in solar panels.