Hi Julie,
This is the welcome forum, so I want to welcome you to ChefTalk :)
We have several forums here for baking and pastry. Normally, our wonderful welcome moderator, "Mezzaluna" would place this message in the pastry forums, but since she is out, may I suggest posting your pastry questions there for better exposure to our pastry experts.
In the meantime, if you need immediate help, I can answer this one: Ganache freezes well, but has a tendency to crack when frozen on the outside of a cake. (I assume you meant "on" and not "inside").
I suggest freezing the ganache and the cake separately, and then icing the cake the day before the event. If you have any further questions on this or any other pastry topic, we'll gladly welcome them in the pastry forums!
