Isn't "up to a year on full charge" also the longest you can leave a Model S parked before the battery goes flat and it's bricked? It does sound like they've calculated their figures based on the cooling never actually kicking in.
Not even. You lose about 1% per day, and then the manual warns that it's bad to let it sit for more than two months after it goes to zero. That's about five months total, if you start from 100%, before something bad happens. I don't think they specify exactly what, but better not to find out.
