When my temporary tag/plate expired, I called the main Tesla number and they sent a message to the location where I picked the car up (outside my state for me). I got an email late that same day from someone at that location with a PDF attachment that contained a new temp tag, I printed it and stuck it over the original tag with clear packing tape.
The same thing happened to a coworker that got his car a couple of weeks before mine, but he was just driving it with an expired plate. I told him what I did, he did the same thing and also got a PDF emailed to him with a fresh expiration date.
We both got our real plates a few weeks later, both leased cars if that matters.