There are, basically, three ways to disable the smart-key system that I can think of:
1. Take the battery out of the key fob.
2. Take the 12-volt battery out of the car.
3. Put the key fob inside a closed, grounded metal box.

The metal box forms a Faraday cage around the key fob, so radio signals cannot penetrate to reach the fob.

Removing either battery every time you park the car is not really practical.
But, keeping a metal box on the dresser, and storing the key in there at night, can be done. And, you might do the same thing at work, perhaps in a metal desk drawer. A metallic pouch, such as an anti-static bag, could be kept in a woman's purse.

I expect the manufacturers will have to do software updates eventually. The original research article suggested a couple of methods to secure the transaction.