Android : How to manually implement device independent scaling using OpenGL ES?

In OpenGL ES 2 for Android, when loading a bitmap as a texture the author explicitly states that he wishes to read the unscaled equivalent of the image. This is done as follows:

/** Returns an unscaled image. Classes should manually dispose the returned bitmap for memory efficiency. **/
public static final Bitmap loadBitmapResource(final Context pContext, final int pBitmapResourceId) {
    /* Load image data. */
    final BitmapFactory.Options lBitmapFactoryOptions = new BitmapFactory.Options();
    /* Disallow automatically scaled image data. */
    lBitmapFactoryOptions.inScaled = false;
    /* Read the image data. */
    final Bitmap lBitmap = BitmapFactory.decodeResource(pContext.getResources(), pBitmapResourceId, lBitmapFactoryOptions);
    return lBitmap;
}

Similarly, all images used in each example application is stored in the drawable-nodpi folder.

As OpenGL performance can be maximised through the use of texture sizes that are powers of two (POT), how then do I go about supporting multiple devices in terms of using device-independent scaling?

Is it preferable to programmatically scale each texture at render time, or instead carry multiple POT images for different DIP scaling?