How long will this frosting keep in the fridge?  I've made way too much and would like to use it on cupcakes I need to make in a week.

Anyone know if that will be alright?

It should be fine as long as you keep it refrigerated until you're ready to use it. I found some brown sugar cream cheese icing after Christmas left over from Thanksgiving. My son wanted a cupcake so i tested it and it was fine so I gave him a little bit on a cupcake. Since cream cheese has a decent shelf life a week should be no problem unless your cream cheese was really old.