Just traded my 60ah i3Rex for the 94ah Rex. I do a 42 miles each way commute, of which half is at 70mph on active cruise control. Range is up by at least 50%, probably slightly more.
As all the commenters here have said, your local conditions make a big difference. Temperature, wind, speed etc. Bottom line is I could rarely get more than 80 miles off the 60ah model. As I write, the stated range on the new car is 133 miles, which is about 25 miles more than the worst reading I have had. I would say a 100+ miles journey at 70mph is way too tight for a non Rex car.
Imperial Blue i3 120ah 2019, replacing 2017 i3 94ah Rex, which replaced 2014 i3 60ah Rex.