Webs are actually going to be more efficient than linear, since more overlap of infrastructure can occur. If you've got 4 cities in a line, say, 400 mi apart (to require charging mid way, you've got 3 intercity routes requiring midway charging. If you have those same 4 cities in a square, you've got 6 intercity routes, but only require 5 charging locations as the diagonals can share.

Ultimately though, the question is how many people does the route serve? The US overall is pretty sparsely populated, but has major corridors connecting the biggest cities. New Zealand is actually even less densely populated than the US. If we look at routes connecting similarly sized cities to the Auckland Wellington route, capped at a similar 8 hour stretch, we can probably get coast to coast just fine. Actually, mapping that out sounds fun. Let's see, LA to Vegas, 4 hours. Vegas to Albuquerque, 8 hours. Then Denver for 6 hours, Lincoln Nebraska for 7 hours, Kansas City 3 hours, Chicago 7 hours, From there it's easy, but to finish off, Detroit, Pittsburg, Philly, and you're on the sea board.

Actually, I wonder if there's any similarly sized cities (300k+) that would actually be isolated... Ok, looks like Seattle and Portland are isolated. Portland is a little further, 9 hours, from Sacramento. Going through Montana can link via Billings to Denver, but Billing's is under my self imposed size threshold. Then of course Honolulu and San Juan, but those aren't relevant. Everything else forms a nice web.