Yes, I did increase the range of my electric cars.
I purchased a 2016 Tesla Model S-60. The car had 210 miles of EPA range. However, it was physically identical to the S-75 with 249 mile range. Only the software lock that controlled how far it could charge and a badge at the back were differences. The price difference was $9,000. Tesla told me at the time that I could buy an upgrade for $9,630.
It was not worth the cost, even though Tesla reduced it a few months later. I didn’t believe it was worth it. The Model S 60 was finally discontinued. Tesla offered to unlock it at a lower price ($2,000), and I accepted. I ordered the upgrade online, and walked out ten minute later to my new S-75. It was EPA rated at 249 miles. The badge was replaced by Tesla Service Centers the next time I visited.
Now, fast forward to 2018. Fast forward to 2018. I purchased a Tesla Model 3 Long Range RWD. It has an EPA range that covers 310 miles. Tesla provided me with an over-the air update which increased the EPA range by 325 miles due to efficiency improvements. Although the Model 3 has the same size battery as my Model S, it is smaller and more efficient.