It could take days or months, based on Tesla's record on previous releases.
If it's a critical release (like when they quietly disabled the air suspension after an accident), it seems Tesla can push the release out to all or many cars in a day or tow.
But for most releases, we seem to go through the same start-stop process. A small group of cars get the release each day, and when Tesla encounters a major problem with the release, they suspend the process - take some time to fix the problem(s) - and then start the process over.
Sometimes I've seen releases shortly after they are announced - and sometimes it's been weeks or longer before my car would get the release pushed.
For a while, you could drive over to the nearest service center and get the release - but it appears they've discontinued that service.
So - I'm back in the mode of looking at my smartphone each morning to see if there is a notification about a new software update...