Cancel the show in that you're not ready, it's that simple
No, I'm not kidding. You don't sell a show that doesn't exist; if you didn't have a Holiday show ready to go two months ago you should never have accepted the gig. This is the sort of lackadaisical antics that hurt magic and the reputation of magicians.
Sure, I could give you a list of things you could do but you wouldn't do any of it justice with just two weeks rehearsal time left (if you started right now).
Take the material you are used to doing and add in a special seasonal effect such as producing Santa (see Mark Wilson's magic course. . . build Santa's Workshop a.k.a. the Arabian Tent and use it as your finale). An alternative would be the Chinese Snow storm but again, you don't have time enough to practice it and get it down pat. . . during the confetti fall however, Santa could just walk onto the stage.
RIGHT NOW is the time to be planning and pulling together material of Valentines & Easter as well as your summer program. You start on the Halloween stuff in March alongside the end of year shows (Yule & New Years). . . that is, if you want to shine as a polished and solid act. This is exactly why talent buyers want to see video; so they know what the product is going to look like. It's why so many legendary acts didn't change much over decades of time and why the working pros isn't up to speed when it comes to the new trendy tricks hitting the market.
I hope you understand my response and take it to heart.