I just made a big mistake.  This is the first time in 25 years I made a cake for the wrong date.  I just made a 12x18 sheet cake, put on an edible image and decorated the whole cake (with buttercream). It happens to be due next Friday, not tomorrow.

My question is, would it be o.k. to freeze this cake.  I'm worried about the edible image when it thaws. Will it be o.k. ??

I can't believe I did this! 

Sure, you can freeze it.  In the post below, scroll down to the 3rd post [by blakescakes] for the instructions:

http://cakecentral.com/t/747425/how-to-freeze-already-decorated-cake-and-then-thaw