I have a 2014 BEV. I'm in the Phoenix area. My commute is 40 miles roundtrip. My Batt. Kappa has been lower than the OP. I have posted my battery concerns on this forum. Took the car to BMW where they said my battery is 92%.
At first I was driving conservative, ECO Pro + and ECO Pro. Tried to keep it 65-70 in the slow lane. After my roundtrip, I would have approx. 25-30 % battery left. Now mind you, this was Oct. to Jan.-Feb. in Phoenix. Temps from 35-60 F.
So, I said screw it. Started driving in Comfort mode 100% of the time. Still drove "pretty conservative" but upped my speeds to 70-75. Enjoying the acceleration when I need it. Now that temps are rising, I still come home with approx 30% battery left.
All of this to say, I believe that my initial "range anxiety" was unfounded. The car seems to be doing well. There are many times I'll get in to go in the mornings after charging ( I do 110v charging every night) that my Guess O Meter says 72-74 miles!
I Love the car for what it is, a commuter car. BMW gave me free Chargepoint charging for the first year and there are plenty around Phoenix.
I don't regret buying this cool, unique car! Now my company has put in 110v charging outlets and I'm able to "top off" at work. Even better!