Tesla recommends (I think it’s the default?) limiting charging to 80% and when they drain as low as 20% they shut down to protect the battery. You’ll need to call a tow truck unless there’s a major emergency/evacuation, then they take advantage of the car’s cellular connection to unlock the last 20% and allow drivers to use the whole battery.

I don’t think the Volt did that. Maybe newer (and more expensive…) GM EVs do though.