All you really need is like 20-30 amps at 240V and most EVs will go from 0 to 100% within a few hours. Which for most people its rare to even need to charge more than 50% every day, unless you're routinely driving over a hundred miles a day. It shouldn't cost $20k to install another 20-30A circuit, unless your home power is already pretty much maxing out your line to your house.

The car can warm itself with the power, you don't need to put it in a semi-heated space.