I was going to make a white chocolate cake with strawberry filling from a Paula Deen magazine. It also has an icing recipe: white chocolate, heaving whipping cream, butter, vanilla and confectioner's sugar...I was concerned about the whipping cream. I had planned to use this icing and the use fondant or should I just use buttercream?
You will do better with buttercream.
The filling with whipping cream should be kept in a fridge. For this filling you will need good buttercream dam.
As for fondant in fridge - it all depends. It depends on the recipe, on the fridge and on the fridge setting. I have several recipes (probably not on CC recipe section at all). Some of these are very problematic, some you can keep in fridge as you like.
With one recipe the worse problem would be the whipping cream itself. I would need to make double buttercream dam to be sure.
Yours fondant could be perfectly fine in fridge or not. From this side of pond I cannot tell you