I have not but plan on doing that drive this summer. It looks like its 190 miles and is feasible in an 85 even with the elevation gain. And it's not going to be that cold when you do it because, if it were cold, the road wouldn't be open!
Note that there are several of the 70 Amp PI-NCW chargers along the way. The one in Mazama would be a good spot to stop and add a little safety cushion. I'd think even just 30 minutes would be enough. Winthrop would also be a good place to get a charge while having lunch. JackA earlier mentioned that the power company is supposedly putting in chargers at Newhalem (iirc). So, no real need to worry.