@ScotT You’ll be aware that there is a suite of Journey data in the i4, including averages since factory, since trip start, since last charge and since manual reset. I have no doubt the OP has achieved an average of 4.2 miles/KWh .
My own average is 3.4, but I saw 4.4 on a gentle but not sedate round trip of 120 miles.
Yes the range in the picture above is only an estimate but at a 4,2 average, 300 miles would be technically quite possible
2024 - BMW i4 Grand Coupe eDrive 35 Sport
2020 - Volvo XC40 T4 Inscription
2017 - Audi Q3 TFSi Sport S-Tronic