Will Frosted Cupcakes Dry Uncovered in Fridge?

Hi there, I couldn't find a definitive answer after searching Cake Central and Google, can someone here help me? I'm a new baker and have made 24 cupcakes to go along with my daughters birthday cake for her first birthday party tomorrow. Right now they are in airtight containers in my fridge, as I made them at about midnight last night! They are still nice and moist, but I want to frost them this morning so they will lock in the moisture for tomorrow. I'm planning to place round fondant circles that have been drying for over a day on top with little pink fondant bows (that I will be making today) to make "minnie mouse" ears after the buttercream hardens a bit. My problem is that after frosting the cupcakes, even without the ears, the container I have the cupcakes in won't be deep enough, and frosting will stick to the top. If I leave these uncovered in my fridge overnight, will they dry out terribly? Should I wait until late in the day so they aren't uncovered as long to frost them? I know many people suggest not refridgerating them, but we are having a heat wave and I'm concerned the buttercream will melt if I leave them out on the counter - not to mention I have kitties and don't want to take a chance.

Thanks in advance for any help anyone can offer! I should add a good friend of mine who will be attending the party is an avid baker and known really well in this area for her cupcakes...I don't want to subject her (or my ego) to dry cupcakes!

Thank you so much for all of your responses! I should have asked further in advance - I wasn't able to check back here in time and went ahead and refridgerated them. Pooh! They didn't dry out too much, but I covered them just to be cautious. The only problem I had was that I used fondant decorations and they turned gooey. Even before I took them out of the fridge they started to sweat and soften (maybe from all the opening and closing I did during the day while baking?) Do you usually use gumpaste in your fondant to keep it firmer longer? Or do you just harden your pieces by leaving it out for a few days and putting it on last minute? The cake I left out of the fridge as it was fondant covered and decorated and I didn't have the same sweaty/gooing issues as I did the cupcakes. Do you think some of the gooing could be from the use of fondant on top of buttercream or is it just because I made the mistake of refridgerating?

In any case I'm grateful for your advice, though I flubbed up this time it wasn't too bad, and you have helped me for the next party I have coming up in about two weeks! Thank you very much!