The good news is that no one needs to be there at the time your box is delivered to sign for it, it will be left by your mail carrier wherever they normally leave your small packages (yay for no alcohol in the box!).
But, because we do recommend refrigeration as soon as possible, if you won’t be home for more than a day after it arrives, it's best to change the shipping address in your account to that of someone who can receive and hold the box for you. (While we would love to simply delay your box for you, as a small operation we sadly don't have the capacity to hold boxes in cold storage after assembly.) As long as someone can refrigerate your box promptly for you, it should be waiting for you in good condition upon your return!