It'll be fine....cream cheese doesn't go bad nor does butter....at least not in 24 hours.
Linda c

I'd be leary leaving cream cheese out overnight, especially in the heat. Food safety recomendations are 2 hours, but if the kitchen is cool, you can stretch that a bit.

Your cupcakes sound delightful!

The worst that can happen to cream cheese frosting is mold. Trust me, it won't mold over night. The amount of sugar in that frosting acts like a preservative. have you ever eaten cream cheese based "mints" at a wedding? They were made a week or more ahead and don't spoil. Believe me you are fine.
But if the storage place is overly warm over night the frosting may get oily and run....but at 70 degrees it should be fine.

I bet they wouldn't mind if you told them what you were bringing and made them Saturday, refrigerated at your house and took them before church on Sunday.

I think they would be alright, but depending on the temperature they might not look as good. I would rather have them refrigerated also.

I think Trixie's suggestion is a good one.

The reason that USDA recommendations are not to exceed 2 hours w/o refrigeration is that trace amounts of mold and bacteria can or may begin to develop after that time. The majority of folks can handle this with no problem, but those with compromised immune systems, pregnant women, young children and the elderly may have issues.

As you can't be certain who will be purchasing your cupcakes, I'd err on the side of caution.

Agreed paulines. The companies that sell cream cheese do not recommend leaving it at room temp for more than 2-3 hours.

I think years ago people's immune system could withstand alot more bacteria, etc. that the regular joe can now.

Thanks, everyone!

Smiles,
Sooz

I don't have any advice to add but want to say that your frosting recipe sounds really good. I'm copying and pasting even though I almost never bake.

Good luck with the sale next week, let us know how it goes.

Lee