First, you might want to check into this stuff carefully, because these type of things generally around things like "placed into service" or "install date" and you dont want to mess around with trying to skate by on a Technicality.
You might have a few days flexibility but you are not going to push it off "weeks". You should just plan on having your install done after Jan 1 2024, if Tesla tries to schedule it before then, tell them you are not available. Trying to delay things on the "other side" of the installation is likely to be frustrating (and perhaps not fruitful for more than a week or so).