AI am in an edible books festival. I am making a 3-D version of oh the places you'll go. I am using dowel rod supports. I will be frosting the cake with buttercream on Sunday, taking it in on Monday, and it will be eaten on Tuesday. The temperature in the library is moderate. I am only frosting in in buttercream, no fondant to drag it down, but I want to make sure it wont melt. Should I use something else? Royal icing? I want it to taste good as well as look good. Please help!

BC doesn't melt unless it's over 85 degrees.
 

AI'm just worried that the tower part is going to fall apart. I'm considering just using rice krises for it.