If you're looking at claimed range of 30 miles NEDC, it makes sense you've never seen it, because the NEDC is a joke. Unfortunately the "fix" is to use the WLTP, which seems to have been designed to unify all the joke systems into a single joke system that eliminates the _really_ bad jokes.
Anyway, back to the trucks ...
At an individual level "megacharging" on such a large pack won't be a big deal since the 85kWh packs are already charged at up to 120kW. In bunches it's just a matter of scaling up. . As long as the use were steady the economics would be good.
In terms of "burden" on the grid:
2014 freight miles by truck were 1,996,165 million. (1)
2016 US utility-scale electricity generation was 4.08 trillion kilowatthours (2)
Using those numbers and wildly guessing at an average load of 20 tons, at 2 kWh/mile making all US truck freight electric would add 4.89% to US electricity demand. Not too bad.
As with all plug-in vehicle technology the success will ultimately come down to whether the costs will fall enough. Fingers crossed.