What I've heard on this angle is that the Tesla maintains the batteries at a safe operating level overnight to enable the owner to drive at any time. They coul

What I've heard on this angle is that the Tesla maintains the batteries at a safe operating level overnight to enable the owner to drive at any time. They could implement a storage mode that allows the batteries to drop below operating temperature while staying above damage temperature, but their software does not yet do that. Tesla has a bit of the Apple approach to software, where they intentionally limit the number of software options to not overwhelm the user. This may change as they continue development, but it's where they are now.