Request an extension of revision deadline over the holidays
Let me recapture my understanding of your situation:


You cannot make an appropriate resubmission in time.
You informed the appropriate person of this fact (hopefully giving appropriate reasoning).


I further assume that:


The person who will decide whether you get an extension can decide on a per-case basis using common sense and is not dogmatically bound to rules.
Further communication cannot possibly have any positive effect.


Then, there is nothing you can do, except hoping the person deciding upon the extension is reasonable and decides in your favour. Whether this is actually the case is something that we cannot predict any better than you. Whether the journal office is open should hardly matter (and again is something that we cannot tell any better than you).