Sure, it's a great gadget for the winter.
The practical side of this is the complications involved with such a modification. If it is done WELL by someone who KNOWS how to properly make such wiring modifications, no problem.
Where the problem comes in with aftermarket electronics is the installation. These installations are usually performed with cheap connectors of various descriptions and usually done by someone with minimal electrical experience.
IMHO, most aftermarket electrical modifications result in problems. Personally, I refuse to take a fine piece of machinery like a 400E and place it in the hands of an electrical butcher. This can lead to so many different kinds of problems you wouldn't believe it.
How do you find someone who can and will do it correctly? I have no idea.
I would NOT do it.