If you're using some money from your car sale towards the MY, definitely sell it a few days early. Need to make sure that check clears in time, otherwise....you'll have to make up the funds elsewhere. I'm doing the same and figure I'll Uber to work for a few days if needed.
Regarding your accessories comment, I got the precut PPF kit from Xpel (Bearded Tesla Guy on YT has a video and a promo code on it from a shop in Canada). I opted for the full front (hood, bumper, panels). Was around 6 to 700ish USD at the time. My local shops are between 2 and 2.5k for the same cover and install. Figure I'd try it myself and see what happens.
Also opted for BASENOR mudflaps on Amazon. They got great reviews but I'm slightly skeptical with them bc they are solid and provide no give. Depending on ground clearance, it could end up being an issue but we will see.