I am making 2 gingerbread houses for a cake and covering them in royal icing, attaching tons of fondant pieces to the gingerbread. Then inserting the house into a cake. Will the gingerbread and royal icing breakdown in the cake and buttercream icing? If so, how long will this take? My daughter's party is Wed. May 4 and i'm scared to assemble everything there for fear of messing up or icing not hardening etc. But i'm scared to preassemble for fear of it falling apart in the truck or the 1.5 hrs of it sitting before it's cut. HELP!!

Please also see:

http://cakecentral.com/cake-decorating-ftopicp-7107897.html#7107897

HTH