I do not cover many cakes in fondant, what is the earliest amount of time prior to the event that the cake can be made and covered in the fondant and still be good?
I made my birthday cake covered in fondant and when we ate the top tier 5 days later, it was ok.
I start to get worried at about day 3 so I think the most I've ever covered is 4 days in advance.
I think it tastes best at day three or four! Heck, we picked at our 4th of July cake for six days after the holiday... we never even covered it, and it still wasn't dry on the inside.
I've been sitting here trying to come up with an answer. Cake doesn't do well in my house. I'm lucky if it makes it to the end of the day (especial if the kids are home on the weekend). LOL I called my sister for an answer for ya.....she says that cake that has been done in fondant is still good at her house for about 4-5days. So we BOTH learned something today.
It's the cake underneath you need to worry about, not the fondant - that will last forever.
Fondant keeps the air off the cake so it will actually preserve it a little longer in terms of the cake going stale but if you have used perishable fillings then they will only last so long...
As there are so many variables (recipe, environment, fillings, coverings etc) I would do a trial run of your cake and see how well it keeps.
I've done 3 days in advance, with both white and chocolate whipped ganache fillings as well as with mousse. Tasted great and still moist.