I'm going to make a mocha cake filled with mocha whip cream and then cover it with fondant.......but they said that once you cover the cake with fondant..you cannot put it in the refrigerator.

I am planning to assemble the cake the night before the event..but afraid that the whip cream filling won't last........

What should I do? How long does the whip cream filling last?

You can put a fondant covered cake in the fridge. When you take it out it will get a bit shiny and sticky from the temperature change. Don't touch it and let the condensation evaporate and it will be fine.

Personally, I don't think your whip cream filling will last overnight with out being refrigerated. I would also think it would cause the cake to settle as the whip cream possibly melted. I found this recipe below here on cc and it says it requires refrigeration.

http://cakecentral.com/recipes/16103/easy-whipped-coffee-filling

I am also aware of something called stabilized whipped cream. I googled for a recipe and found the recipe below which still states that it needs to be refrigerated. I am not aware of a whipped cream filling which does not need to be refrigerated. If it were me, I would either make the cake the day of the event or I'd be googling other mocha filling recipes.
That's about all of my two cents worth. I hope this helps.
WHIPPED CREAM STABILIZER  

1 tsp. unflavored gelatin
1 c. heavy whipping cream, at least 24 hours old
4 tsp. cold water
1/4 c. powdered sugar
1/4 tsp. vanilla

Combine gelatin and water. Let stand until thick. Then place over low heat, stirring constantly, until gelatin dissolves, which takes about 3 minutes. Whip cream with 1/4 cup confectioners' sugar and 1/4 teaspoon vanilla, just until it is slightly thickened. While beating slowly, gradually add gelatin to whipped cream mixture. Whip at high speed until stiff. Cakes frosted with whipped cream should always be refrigerated.

Here's another recipe from the cc website. This looks like it would be able to sit out overnight.

Good Luck too you!
tokazodo

http://cakecentral.com/recipes/7571/chocolate-mocha-filling

Thanks sooo much for your immediate reply. Actually I'm thinking of making it mocha buttercream instead...but my friend said that they don't like very sweet filling........but i am also thinking what Kimmers971 advised.

Thanks tokazodo for the recipes and advice!

Like everyone said, it should be fine in the refridgerator. I just wanted to remind you that if you have an 3D fondant decorations (by that I mean ones that are to stand upright) they will "wilt." I did this just last week for only a couple of hours and the decorations I made got soft and floppy and fell over in the refridgerator. I knew better, but I did it anyway.

when I use whipped cream I normally make a dam of really strong butter cream around and then fill the middle with cream. I also refrigerate my fondant cakes all the time, I think it makes the fondant hard and sturdy so the cakes are more travel ready. I also tell the people to keep the cakes refrigerated untill 20 mins before they are ready to serve it, So the cake is cut when condensation is starting and the fondant is not too hard or too sift yet.

you could use Rich's bettercreme which does not need to be kept in the fridge. According to their website, applied to cake and kept cooler than 80 degrees it willhold for 5 days.
http://www.richfoodservice.com/product_detail.cfm?cId=72&scId=7237&pId=4591

Check out this thread, it has tons of recipe ideas I am sure there is one for mocha-or you can pm the op (Melvira) she is a wiz with this stuff.

http://cakecentral.com/modules.php?name=Forums&file=viewtopic&t=601193&postdays=0&postorder=asc&&start=0

p.s. it is super easy to work with, and yummy!

Thanks cakesbyamber! Maybe i'll just cover the cake with fondant and place it in the refrigerator overnight and just add the fondant/gumpaste details by tomorrow. Thanks again!!!

If you make a whipped cream mousse using heavy whipping cream and instant pudding it will hold for days. I have left it in the fridge for a week and it was still fine. When working with whipped cream I don't use anything else. There are so many flavor options it's the best I think you would be surprised how yummy it is if you tried it.

Regarding the whipped cream mousse, did you use that in place of buttercream and it holds similarly to buttercream and can hold up to fondant pretty well?

AI once forgot to put some leftover cake which was whipped cream filled in the refrigerator ...it stayed over night and stayed fine, it didn't melt