How to handle not-enough-isolatedstorage issue deep in data loader?

Question

I have a silverlight application which loads data from many external data sources into IsolatedStorage, and while loading any of these sources if it does not have enough IsolatedStorage, it ends up in a catch statement. At that point in that catch statement I would like to ask the user to click a button to approve silverlight to increase the IsolatedStorage capacity.

The problem is, although I have a "SwitchPage()" method with which I display a page, if I access it at this point it is too deep in the loading process and the application always goes into an endless loop, hangs and crashes.

I need a way to branch out of the application completely somehow to an independent UserControl which has a button and code behind which does the increase logic.

What is a solution for an application to be able to branch out of a loading process catch statement like this, display a user control which has a button to ask the user to increase the IsolatedStorage?

public static void SaveBitmapImageToIsolatedStorageFile(OpenReadCompletedEventArgs e, string fileName)
{
    try
    {
        using (IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication())
        {
            using (IsolatedStorageFileStream isfs = new IsolatedStorageFileStream(fileName, FileMode.Create, isf))
            {
                Int64 imgLen = (Int64)e.Result.Length;
                byte[] b = new byte[imgLen];
                e.Result.Read(b, 0, b.Length);
                isfs.Write(b, 0, b.Length);
                isfs.Flush();
                isfs.Close();
                isf.Dispose();
            }
        }
    }
    catch (IsolatedStorageException)
    {
        //handle: present user with button to increase isolated storage
    }
    catch (TargetInvocationException)
    {
        //handle: not saved
    }
}