I would go with 400A NO QUESTION at this point given your plans, even without the tankless (which I would not consider if electric). I would not even guess at a price considering your location and the fact that we know nothing about the site details.

If you live where winters are cold, I'd suggest a hybrid. All-electric vehicles have power issues with the batteries in very cold weather. I am not a fan of Toyotas - I find them unexciting to drive - but they do have an extensive line-up of hybrid vehicles. They have hybrid versions of both the RAV 4 compact SUV and the bigger Highlander SUV. However, you should note that several pro reviews have said the actual mileage in testing the Highlander hybrid wasn't more than 1-2mpg better than the gas engine model. One reason I dislike electrics and some hybrids is the CVT tranny and/or regen braking. I hate the driving characteristics of the CVT since I live in the hills, and regen braking takes getting used to. Toyota has done a poor job in the hybrid Highlander with the regen braking system; Car & Driver really dinged them for it. C&D preferred the RAV 4, although it's pricey. US News has a page that compares the RAV4 hybrid, Nissan Rogue hybrid, and the Honda CR-V: https://cars.usnews.com/cars-trucks/toyota/rav4-hybrid I will say I'm not a lover of Nissan (CVTs in all vehicles, gas, hybrid and electric), but it's because they rate lower in reliability than Toyota or Honda. Note that some hybrids have regular transmissions and standard brakes, so you need to be careful about what you're buying. I love my 2017 Ford Edge Sport AWD SUV, which is the best handling vehicle I've had since our old Acura Integra, but was not overly impressed with the 2017 Ford Fusion (sedan) hybrid I drove recently as a loaner. Ford and Hyundai/Kia were very late getting into the hybrid market so they are still in first-gen stage, so I wouldn't recommend either mfg for hybrids at this point.

"At that length, I would seriously think about using 8/3. There are per-foot loss equations, but I'm too lazy to look them up." IIRC, the code recommends, but doesn't require, a maximum of 5% voltage drop. At 24 amps (80% load), 200 feet of AWG 10 copper wire (0.2 ohms) has a voltage drop of E = I * R = 24 * 0.2 = 4.8 volts, which is 2% of 240 volts. So you'd be well within the guidelines with AWG 10 cable. You could go with the larger wire and get improved efficiency. At 24 amps (80% load), 200 feet of AWG 8 copper wire (0.126 ohms) has a voltage drop of E = I * R = 24 * 0.126 = 3.024 volts, which is 1.3% of 240 volts. "The Leaf only charges at 20A so 6 gauge is overkill but future proofing makes sense." Just make sure that the terminals on the breaker and receptacle you use are rated for the size of the conductor you install. For example, a Square D QO 30 amp breaker is rated for wire sizes from AWG 14 to AWG 8. Installing it with AWG 6 wire would be a code violation, and might not even be physically possible. "'(Actually I've never seen a 5.76 kW EVSE mentioned, but I have seen 5 kW and 5.5 kW.) ' "That's because you used 30 amps in your figures. They would need to be less in order to use a 30-amp circuit at a lower amperage." Not really. I calculated in the 80% continuous load factor: 30 * 240 * 0.8 = 5760. I guess I wasn't clear. Sorry. I was just trying to point out that nobody I know of manufactures a 5.76 kW EVSE, so you'd have to install one below that capacity (such as 5.0 kW or 5.5 kW). "Don't have to imagine [incompatible gas stations]. I'm old enough to remember this when lead was removed from gasoline. There were two different nozzle sizes, and the old nozzles would not fit in new cars." I was there too! But as I see it, there are a couple of differences between then and now. One difference is that unleaded pump nozzles would fit into older cars designed for leaded fuel, whereas CHAdeMO and CCS connectors and data formats are totally incompatible.. So today, you can't use a CHAdeMO EVSE with your BMW I3; but back then, you COULD pump unleaded fuel into your 1962 Ford Galaxie. (However, if you had, your car's engine might have been damaged.) The other difference is that (as far as I can recall) every gas station had both leaded and unleaded fuel for many years after the 1975 introduction of automotive catalytic converters.

It's a cool thing, but not all EV producers support this. In particular, Tesla specifically says that if you use the car to provide backup power to your house it can void the warranty on the car battery. I believe it has to do with the fact that doing this could lead to degradation of the battery, which may be an issue for other EV batteries unless the manufacturer specifically endorses it. Here is some more info: Don't power your home with Tesla car battery