You should be able to make it easy from Groveland to Hawthorne via Tioga Pass. US395 north from Lee Vining, then California 127/NV359 NE to Hawthorne.
All roads are well maintained. You do climb a little heading out of California, but then descend into Hawthorne. I have driven this road a number of times in ICE years ago.
EVTripplanner says that I can make it from Fish Camp to Hawthorne in my old S85 with about 15% remaining in the battery.
I would not sweat that leg. It is to and from the park near Berlin NV that might be tricky.