Hi Laura,
We’ve been using chocolate ganache for a couple of months so we’re not an expert but have learnt from watching Paul Bradford (www.designer-cakes.com). You shouldn’t have to fridge the cake as once its set unless the temperature is very hot it should stay set. Depending on what ganache you use you should only need to fridge the cake for an hour, if at all. All will set out the fridge. Dark chocolate sets very quickly whereas milk and white take quite a bit longer so do tend to need fridging. When covering in fondant, you just wait till its set and the natural moisture should stick the fondant. If you have any probs sticking the icing if u just rub the ganache with a palette knife it disturbs it making the fondant stick. Ive only used ganache a few times but I prefer using it to buttercream as so versatile plus a nice flavour. Most of the cakes we’ve posted recently are ganached cakes covered in fondant (spiderman, peppa pig). As I said Im not an expert and only know what Ive learnt through that website and experience but hope this helps xx
