Considering that the imperius curse can be fought only through sheer willpower, and considering sleep, even a magically induced sleep, is a state of high vulnerability, could the imperius curse be used to wake someone from their slumber if only for as long as they are under the influence of the curse?
More generally speaking this raises the issue of potion and spell interaction, and how much, with a few exceptions, potions seem to be underestimated in the series as a means of direct action.