That is my concern, we often go to Clemson football games and it is close to a 300 mile round trip. And after leaving early in the morning and. Tailgating, then watching the game, the drive home gets us home after 11:00 and even later depending on the kick off time. So I really wouldn't want have to wait a long time to charge to get home... It is a long day already. I sure wouldn't want to be dealing with range anxiety at the end of that long day
I think that will be a stretch, especially if you are driving spirited, or the weather is bad, or route is hilly. I would plan for 1 15-30 minute stop on route at Electrify America (if on route?) On your example, you can always stop and do a quick top up before you arrive at the game, then drive straight home afterwards. I do this when we go to Vancouver Canada, I top up before I cross the border, so once in Canada we can do our touring, and not have to worry about finding chargers in Canada, or foreign transaction fees. Making a quick charging stop is no biggie, and for our family we make it fun, and even discuss it, no anxiety, it's just the reality. In my experience, someone in the car always needs to stop, before the car needs to stop. The kids even talk about where the best (fastest) chargers are, and best snacks.
Remember, EV batteries do not like to get fully discharged, think of it like redlining an engine, it's OK once in a while, but should be avoided regularly for best longevity. I rarely run my EV's below 20% SOC (never below 10% unless it was an emergency), and typically plug in around 30-40%. We will have to see how GM sets up the battery on the Hummer Ev, will they have a big top and bottom buffer? In that case charging to 100% is no issue (like E-Tron), or will they be more like Tesla where when the car indicates 100% that is really 100% (spring is wound tight). I only charge my Model Y to 90% regularly as recommended by Tesla.