Cutting out in the cold

Hi, I've recently had some issues with the bike and wonder if anyone knows the cause.
The problem is that after a cold ride (40 mins at 80mph at 5 degrees) the engine will stall if the revs are cut. After I come off the motorway if I pull the clutch in the revs will drop to below 1000rpm for a moment and if you dont gas it back up it cuts out. The faster I do the motorway section (the colder it is) the worse it is once I'm on back roads. As well as cutting out during normal riding the power comes and goes. The bike has no problems starting in the cold and was fine before the weather turned bad + had a service less than 500 miles ago.

The bike is an 06 model sv650s and is fitted with a suzuki restricted ECU.

Any ideas?
Thanks