From my understanding, once you have the client downloaded and your early access starts, you will be able to play for the remainder of the early access time. During this time without the code from your CE edition you will not be able to access those items.
Once the early access time ends you will receive 30 days of free playtime with the purchase of the game (all versions I believe). Whether this will be tied to your CE inbox code or not, I am not sure. I would guess that since you entered your preorder code that once the early access time ends you could simply enter your info (cc# and personal info) and continue to play from where ever you are.
Once you get home you can enter your CE code from the box and receive your rewards for that edition.
I am not sure if there will be a code in the box, for the physical copy, to play past the early access. I would hope for your case that the preorder code that you registered on the site would allow you to continue to play past early access. If no, then you may not be able to play the game past early access. In that case, enjoy the vaction and the holidays and when you get back the starter zones should be fairly less populated.