Yes, it "sounds" like good news indeed...but I live and travel along the same freeways as you and I've been driving EVs for the past six years and I don't think it's realistic.
We don't have to speculate too much because we know the math. The SR has a 98 kWh battery. The best efficiency you can hope for at freeway speeds is ~2 mi/kwh, which is 196 miles
at best. That's without accounting for speeding, elevation changes, wind resistance, weather (A/C
or heat...sometimes
and heat where you and I live/travel), or battery degradation.
Now, if you're putting along in the slow lane, dodging semis, this won't matter to you much. But if you're trying to keep up with the flow of traffic, which is going to be somewhere in the 80s-90s, you'll be lucky to hit 1.6mi/kwh and might even be looking at 1mi/kwh. That's why I said if you're going to drive at 60mph you'll be fine, but if you drive at 75 (70 mph rural CA highway speed limit + 5mph) you won't be.
I wouldn't risk rolling into a charger with only 5-10miles on the ticker because we just aren't there yet. That charger may or may not be operable. It may or may not deliver anything more than a 20A EVSE could deliver.
I hope people giving you advise understand that you're driving through the
Mojave Desert--one of the most inhospitable regions in the
world. We're seeing daytime temps of 130F but that's not the worst of it...we're seeing 120F at
night. I haven't even mentioned the out-of-the-blue 40+ mph dust storms that can blow a vehicle off the road.
When most folks think of CA they see a meandering freeway up the coastline going through some of our nation's most populous cities. Most have no idea that just 100 miles east there's an entirely different environment that can, and does, literally kill motorists who become stranded in their vehicles and are hours away from recovery/rescue services.
Sorry if this came across as soap boxy or too pessimistic, but if you were asking about committing from OC to SD, for example, I'd suggest you wing it. Given what we know about this truck's efficiency, the battery size, and the state of charging in the US as a whole and the eastern side of rural CA in particular, I'd say you are right up against the margins of safety here. The Mojave Desert isn't a place I would advise anyone to play up against the margins.