Found a few more things about their trip... they're travelling with an RV and either one other vehicle or trailer (containing a 2nd i-MiEV, mostly for display at events along the way) which means they could be looking for RV camping sites (240v / 50A service) for fast recharges.
OR they've got a genset in the back and they're charging en route.
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Interestingly, the EV club from the University of British Columbia just left the west coast in a converted, classic Beetle loaded with lithium, and they plan to cross the country in 2 weeks. If so,
they'll be the first EV to cross the country. It's a race!
Range of their car: 300 km (~200 mi) @ 100 km/h (~60 mph) according to their site.
UBC Electric Car Club