~500km across at the widest, yes. But you can't (realistically) drive across the country. The middle of the country (the highlands) is like offroading, and is closed for most of the year. You drive the Ring Road around the country. With the
shortcut in Axarvegur it's ~1250km (776mi) to drive the full circle, ~1310km (814mi) without the shortcut.
Also remember that the country is mountainous and that very windy, wintery conditions dominate for many months (particularly in the passes).
Even just going through fractions of the country can be surprisingly long distances. For example,
Vestfirðir, the "fjördy" area in the northwest. Starting at the planned Supercharger site at
Staðarskáli, driving to
Ísafjörður along the north coast, back along the south coast, and returning to Staðarskáli via the shortest path, is 707km (439mi). Again, full of mountain passes. And going to these places aren't just hypotheticals; one of my best friends lives in Vestfirðir. Another lives in
Ólafsfjörður, north of Akureyri. And I love going to music festivals, which are all over the country in remote places - like
Bræðslan, in
Borgarfjörður Eystri. The longest route (non-circle) between two towns is Grundarbær (NW of Bolungarvík) to Ulfstaðir (S of Borgarfjörður Eystri), at 905km (562mi). Even on the Ring Road itself, the distance between points of "civilization" can be quite long - for example, Reykjahlíð to Skjöldólfsstaðir, 111km (69mi), through some rather high terrain. Between there, there's not even a farm you could stop at for more power;
it's like driving across the moon (indeed, the Apollo astronauts
did their geology training not far to the south of there!)
We need range and fast charging. It's a requirement.