I don't have that type but as winters became milder I changed from the home made bubble/foil insulation over a steel frame handlebar muffs I put on every winter and removed in spring for over 20 years with a set of Dnepr/Ural type hand guards that I leave on year round. They do a pretty good job of keeping my hands out of the wind & rain.
A few years later I had to drive the summer machine to an appointment in another town on a cold, wet fall day so I wore my insulated leather mitts but the wind pressure on them made it hard to move my fingers onto the levers so when I got home I ordered these hand guards for it. They don't protect my hands as much as the Dnepr/Ural ones do but they make a big difference on cool days and in fact I sometimes need to move my hands so that the wind can blow up my sleeves on hot days.