We went 159.7 miles with one 4.81 kWh fast charge boost and exactly 5 gallons of gas (ran out of fuel before cresting Blewett Pass and made it over the top with less than two bars). That last 26 miles into Leavenworth almost made me nervous, but we finished up with less than one mile on the turtle, after the downhill grade leveled out in town.

I think Volt drivers would call that 32 mpg in Mountain Mode. TESLA drivers might call it a hamburger run... My wife calls it tolerant.

Similar results on the return trip, though we took a longer route and refueled once; no CHAdeMO.
As mentioned when I made this trip on electric only last year, the i-MiEV can barely maintain regen at highway speed, even with miles of 7% grade- UNLESS you've got a pusher behind you. Then it's full regen at cruising speed (with instant engine braking at your disposal in case of elk encounters).
Thank you PV1. I'll agree that CHAdeMO is my preferred range extender within the metro area, but the novelty quickly wore off for highway trips, especially when trying to keep a schedule but running into lineups of LEAFs or a DCFC station out of order.