Certainly it seems that the researchers in the article weren't trying for a real-world solution. Most basic research just gives us more questions to answer. I mostly posted the article to respond to the first poster's question: YES, researchers agree that the cold affects hybrid batteries and decreases their efficiency (which differs a bit from the advice above of randomhelloguy) and the industry knew this years ago so it's probably reflected in existing or upcoming technology.

With respect to everyone who has suggestions for fixes, we probably don't want the ultimate solution to be- buy the car, then open it up and change around bits of it to jerry-rig some other configuration. We want the cars to be built in such a way as to let the energy be used as efficiently as possible in the first place, right? In terms of energy conservation, of course it's a tradeoff between using energy generated from the ICE or from the battery to achieve better initial temperatures and performance, but in cold conditions, those two sources are not equal. External plug-in power sources aside, the inside of the car ought to be arranged so that it's most efficient, and that means addressing known weaknesses like this temperature problem in future incarnations of the technology. I'm not proposing any solutions, because that is outside the scope of my knowledge, but I thought I'd share the link in case any of you found it informative.