There are many diseases that currently infect English ivy, particularly old beds of ivy. Here is our webpage about them: http://extension.umd.edu/learn/ivy-leaf-spot-english-ivy The diseases do not kill quickly, so we suspect that your bed has been infected for some time and that this past severe winter has put it over the edge. (Deer will also browse English ivy when there is enough deer pressure and they are hungry enough.) A south slope can also encourage winter burn which makes broad-leaved evergreen plants drop brown leaves. The roots would not be dead in either above case (deer or winterburn) and will regrow on their own without your help.
However, English ivy is a tremendous problem in Maryland . It is a foreign plant andhighly agressive, smothering and outcompeting native plants. This invasive plant isn't a problem when controlled in a yard, but when it climbs trees it can produce berries which birds spread far and wide, taking over parks and natural areas. It should never be planted where it can get into parkland. In addition, CO2 levels have gone up and this increases vine growth rate. We see that you have healthy pachysandra.This is not native either, but it is not nearly as problematic as English ivy. You may want to encourage it, and replant any dead areas with native plants such as shrubs and, especially, ferns. Here is a very good online publication of native plants with photos and growth requirements that you might find helpful: "Native Plants for Wildlife Habitat and Conservation Landscaping: Chesapeak Bay Watershed."