Have not taken such a trip. However, based on what I saw in the elevation changes, you will be transiting through several high-altitude (4,000ft to 5,000ft) passes, I'd be quite conservative in my range estimation. The Pure has an EPA rated range of ~400 miles. If your average speed is 70mph, I'd assume a de-rated range of no more than 200 miles per full charge (100%) or perhaps 160 miles between charges. You can always slow down to below 60mph to conserve if you run low. Just make sure you have charging facilities en route.