I don't know if this will work in your application, but consider the idea of mounting a microlink under a soffit. It dramatically reduces the exposure from direct sunlight. Unfortunately, if the house is white, or you are near a pool, or you wear mirrors on your shoes (doesn't everybody?), the reflections will lock you up. Xantech waterpad is clearly the consistently reliable piece I have worked with, with the added benefit of not having to find the remote.