I've been storing TOTP codes in on my Yubikeys for many years now, it works pretty decently. They have an app for it (https://www.yubico.com/products/yubico-authenticator) which has gotten better over the years. For redundancy I've stored keys on two devices.
As it happens this has been in the news quite a bit, and we've been told that the Finnish trunk lines are built for this [1]. Finland isn't split up into multiple electricity price areas unlike its neighbors.
Are you sure? I have a VAG group car with the same sync button and it simply ensures that the set temperature is the same on both sides of the car. As this car already looks like it has automatic AC that shouldn’t require additional hardware, unless this is some fancier ”sync” than mine..