I think he means less power per total overall volume of the vehicle. SUVs are certainly less efficient per mile, but their power requirements don't scale linearly with volume so you have a lot more "extra" room to place batteries, even if it is still entirely within the frame. So you can get away with less space efficient batteries.

Drag scales by frontal area (and the coefficient of drag tends to actually be lower on longer objects), so as long as the SUV is longer than a sedan, it'll tend to have less aerodynamic drag proportionally (rolling resistance scales with weight, though, so you still have to pay that cost).

An observation is the amount of power needed is proportional to some log of size and weight.