Okay, my car seems to be maintaining itself at approximately 50 km ideal (ignoring range reserve). Looks like it might be topping up nightly, just a little bit. That might perhaps not be the most efficient way to do things, since if it's cold it would have to warm the pack first. This is the first time I've had my Roadster parked for the whole winter. In previous years I've had it out occasionally for one reason or another, so it never really bottomed out in Storage mode.