I test drove a Model-S last week.A fella had driven one in to Kansas City,Missouri from Florida,on 4-stops.
In the 1980s,I constructed a fairly streamlined 'top' for a utility trailer for my Honda CRX.
On a round trip from Texas to California,hauling a 1/4-ton of batteries on the return leg,I only lost 2-mpg,compared to 'naked.'(50-mpg vs 52mpg)
If you pay as much attention to the lower part of the trailer as the top,I suspect that you can pull the trailer with no loss to range at all.
