While I find my i3 is comfortable for me running around, I do not find it overly comfortable on a longer trip, so even if it could go further, I would not want to, which is why I kept my other car. I realize not everyone can justify that, but for me, even if there were reliable CCS units along my route, it would not be my first choice for a longer road trip, REx or not. It's hard enough to find a L2 EVSE, let alone a CCS unit at places that would be convenient. WHere you live can make a huge difference. I'm hoping that sometime in the future, a serial hybrid, maybe the i5, would provide my EV running around town, and long distance travel in one vehicle, but only time will tell. In the interim, I've not been inconvenienced by my BEV, but being retired, I get to pick and choose not only the time, but the places I want to be. Everyone's situation is different. But, for many, the REx option is mainly for relieving anxiety. Because they have it, they make plans accordingly, but I do the same thing with my BEV and saved the cost and maintenance.
2014 i3 BEV, 2021 X5 45e
(The i3 will be sold soon, <17K-miles, interested?)