I’m fortunate enough to live nearby Apple headquarters in Silicon Valley so I went to pick mine up in person when released, but I’ve also ordered online before. It told me it would show up one date and arrived almost a week before that date. It was literally overnighted from Shanghai somehow and at my doorstep the next morning. No idea how but that’s the tracking info. I’d imagine yours would show up before the date they gave you
Apple HQ new and old (1 Infinite Loop) are within easy driving distance for me. But neither has had stock since before Thanksgiving. I guess I should not have waited more than a few days to decide to buy an M1 system.