MkBHD, who is 6’2" and a professional athlete, does a height check in every EV he does a video about, including the back seat where applicable. I don’t recall him ever saying that he couldn’t fit in an EV.
It’s hardly surprising that car manufacturers design their products based on average human sizes. That’s just good practice.
500km is no big deal for most modern EVs. You don’t need a “range king” for this trip unless you are determined to do it without stopping at all, but it sounds like you are accustomed to a single stop already.
A single 20 minute recharge at a decently fast charger somewhere in the middle of your trip would be sufficient, and given your country has plenty of charging infrastructure I’m guessing you have plenty of choices to charge.
Cars with 2 x ICE has been done several times, there’s quite a number of them: https://www.carthrottle.com/news/6-twin-engined-cars-proved-one-powertrain-simply-wasnt-enough
It’s generally not a very good idea though.