I have just had this chat with BMW over my 2014 GS, after a day of testing they tell me that the grips on the can bus equipped models (not just the GS) are significantly cooler (5 deg C at least) than the pre can bus models, and at the moment there is no fix avalible for this.
As has been suggested on here, the fit oxford grips option would seem to cause its own issues, the main one being a warranty issue, as you have removed an integral part of the bikes equipment, you may invalidate any warranty, also as the clutch side has the control wheel on it, this could be affected by an aftermarket grip, along with the issue of them not working with the can bus system, unless you put them directly to the battery that is, but why would you do this to a new bike, better to get the fitted ones to work as they should.
The dealer suggested to me that the best option is to get as many owners who have the problem to contact BMW / MCN /Ride /Bike etc, get the problem talked about in the press and via the dealers, and this may prompt a software update to the system.
Heated grips are needed when it's cold, and it seems that under these conditions they are to cold, would you want ABS that does not work in slippery conditions?