[oil pan 4]

If the dc to dc converter and inverter is super efficient (it's possible) and the car gets driven like 12 mph yeah it might hit 10 miles per kwh.
I hear people who use their leaf as its design intended can hit 6 to 7 miles per kwh, which is using it at low speeds in the city. If the leaf had a super efficient drive system and eliminate most of the stand by losses, which is about 700 watts on a leaf like mine, might hit 10 miles per kwh.
But if you drive on the highway and use A/C you won't see anything near 10 miles per kwh, more like 5 miles per kwh.

Don't spend 30,000 on a leaf, get a used one a few years old for around 10,000.