You can definitely use frozen cake or cake crumbs from the freezer. In my family, everyone has their own favorite, so I always keep a number of bags of crumbs of different flavors in my freezer so that I don't have to make 48 of the same flavor at once! Each time I bake a cake for pops, I split it down, weight out into equal portions of 2, 3 or 4, and freeze what I don't need for another time.
The crumbs defrost easily and can then be mixed with the frosting of your choice.
I have noticed that it depends a great deal on the moistness of your cake as to how much frosting you want to include. For example, previously I had a red velvet cake that was so moist it only required a couple of tablespoons of the frosting to form the "dough" to be rolled into cake balls. Whereas before I've had to use most of a store-bought tub of frosting to get the same dough consistency when the crumbs were much drier.
I have stored cake pops in the fridge and frozen fully dipped and decorated pops in the past and encountered the "sweating" problem as they defrosted or cooled. Where the cake pops were frozen, the condensation then made the cake pop tacky to the touch. As Kiddiekakes rightly said, it makes a difference if you live in a hotter area (I'm in Los Angeles) where your cake pop warms up more quickly. So maybe move them from the fridge into a cooler room first.
You can store cake pops at room temperature happily for a week or so.
Hope this helps!
I've been keeping experimenting and logging my progress with all kinds of cake pop recipes on my blog at www.cakepoprecipes.org
if you'd be interested.
Best of luck!