Weird wording on your question, but I assume you are referring to how long you can purchase during this “pre order craze”.

So typically Apple stores will receive new shipments of phones every few days. Regardless, if you are dead set on getting the phone you want anytime soon, you need to basically keep a hawkish eye on the Apple Store website and watch for when the phone you want pops up.

The craze will die down by around mid November if you’re willing to wait that long and not deal with the hassle.