I spent one winter at the particular location in Germany and the snow was quite challenging there on occasions, sticking to a bike when riding over agricultural roads and making it look as if it belonged to a snowman
. The brakes were obviously completely taken out of operation.
My leaning is towards indexed, but I am not dogmatic about that. I did offbeat things though for the cause in the past such as RHS on the left, Shiftmate and microstops with redundant stops filled with epoxy.