Could anyone please share with me what the life expectancy of buttercream is at room temperature?

I use Wilton's Buttercream Recipe (1/2 butter-1/2 short.-Milk) and need to decorate a cake tonight due Wednesday night. Due to its size, I am unable to refrigerate it. The filling is Chocolate Ganache and it will be covered with Crusting Buttercream. Will the cake survive until Wednesday night?

Your feedback will be greatly appreciated.

Thank you!

it should be just fine. I leave buttercream out in a sealed airtight container for a week or longer and it tastes just fine. the sugar acts as a preservative for the milk, cream, butter, whatever that might ordinarily go sour.

I'd at least put the cake in a large box though to protect it from dust, etc.

Thank you very much.

Thank you very much.