Buttercream cakes need the fridge. Fondant cakes do not — and the fridge actively hurts them. This is the single most common mistake we see.
Why. Fondant is a sugar paste. When you take a fridge-cold fondant cake out into a room at 28°C, water condenses on the fondant surface. The fondant absorbs that water, becomes sticky and patchy, and any piping or sugar work on top can dissolve.
What to do instead. Leave the cake at room temperature in a cool dry cupboard, inside the original cardboard box (the box absorbs any tiny condensation from inside the cake). The interior of the cake (sponge, filling) is protected by the fondant exterior — it stays fresh for 48 hours.
What if the room is very hot. If your home interior is above 30°C, run the AC in the room. Do not move to the fridge.
Once the cake is cut. Now the interior is exposed. At this point you can refrigerate the cut pieces with the fondant exterior side facing outward. Best to consume within 24 hours of cutting.
For multi-day events (a Sangeet on Friday, a reception on Saturday): we deliver fresh cake each day. Storing wedding-cake quality fondant cakes for multiple days at home is hard to do well.