Okay, so I am a bit late coming to this thread, but here's my experience.
My other bike is a Triumph RIII, which I have put 100,000 miles on in all conditions. I have only about 5,000 miles on my RE so far, but they are climbing. Therefore most of my winter riding was done on my other bike.
I have heated grips, which are good, but warm only the insides of my hands. I purchased some inexpensive heated gloves and they warm the outside of my hands. With the grips and the gloves things were better. However, the cheap gloves died every season - but were replaced under warranty - so I replaced them with better quality gloves. They were much better. However, there is a bit of mucking around getting them on and off with the wiring and they still are not toasty warm at 10-15F with a 70mph windchill. So I got some Hippo Hands.
The Hippo Hands are excellent. I can wear light gloves, turn the heated grips on low, and ride all day with toasty warm hands. With even slightly thicker gloves I don't need the heated grips. I have not had a problem with them blowing back onto the controls, but if I did then I would have bolted a length of aluminium onto the bar ends to keep them forward. The only downside of the Hippo Hands is that they are ugly. However, the beauty of warmth overrides the lack of beauteous looks.