It's probably at half of Prime's lifetime numbers in its first month (~3 weeks).
Holiday sales will tell us a lot. Is it going to dwindle after the first few weeks because everyone who wanted it picked it up when it came out (think Zelda: LA's remake) or will it be a solid holiday seller.
Hopefully it'll at least be over 2 million worldwide at end of year.
I'd think minimum it will sell is 3 million. I think 4 million is likely. 5 million is a maybe and probably depends on price cut at some point and if future Switch Metroid games reignite a selling spree for Dread when they come out.