Making cake in advance

Hi, you can ac tually make each tier, cover it in fondant, put in cake box,wrap box with 3 layers of saran wrap, then wrap with heavy foil.You  would then take out of freezer and put in fridge , fo 24 hrs.still covered. After it thaws, then unwrap and put decos on. You could put all decos on, when you fix to put in freezer, except i would not put the big bow on until you take from fridge. Let sit out from fridge for a while , before finishing it. Lot s of decorators do this. hth

Freezing is fine but it isn't really necessary to cover in 4 layers plus a box.  If you want to, go ahead but it will be fine with much less.  They did an experiment on the Wilton forum and froze uncovered along with covered cake in the freezer and they came out the same.  I cover with one layer of something to keep it clean but you are only talking a few days in the freezer. 
 

sending this to show you the response from blakescakes. I listen to people that know what they are talking about and have more experience than i do. hth    SCROLL DOWN TO BLAKESCAKES POST. You said you needed help for saving you time. we all do.

http://cakecentral.com/t/747729/can-i-really-freeze-an-iced-cake

I know some advocate multiple layers, I  just haven't read any justification for so many layers.  It is just overkill to me.  There are lots of others who use one layer or two or three or whatever, it isn't like 4 plus a box is the only way and anything less will be a fail.  Think of the products in the freezer section of the grocery store that are stored for months, ice cream with just a waxy box, cakes in a box, pizza and multiple bread products all in one layer of plastic, etc, etc.  The poster is only going to be storing it for a short time.  I have frozen things multiple times in one layer of saran wrap or a zip lock or a plastic storage container and they defrost just fine.  I just wanted to mention another option to the poster.
 

It was my Wilton instructor who taught me how to freeze & defrost a completed cake.  She encouraged using multiple layers because: saran wrap (at least the type that comes off of rolls) can have micro perforations in it, so 2 layers makes it all the more patent AND home freezers and refrigerators vary a lot and can contain smelly things.  Odors can be insidious, so extra protection is just a form of insurance.

It's up to the decorator as to how much "insurance" they want to invest in, I guess.  I tend to over-insure whenever I have the option. 

I've had great success with the method, freezing white fondant covered cakes with ruby red accents and graduation cakes with large fluffy bows.  I know that when a client (or I) must freeze a cake, it will absolutely, positively look and taste like it was made "day of", as long a it's done this way.

Hope all goes well with your cake.

Rae