The Merlin/EH101 incorporates anti-ice (to stop ice accretion) on the tail rotor and de-ice (allow to accrue then shed) systems on the main rotor. Both systems are electrical and rely on heating elements in the blades. The de-ice programme changes depending on OAT and liquid water content. You will still get an increase in wt and parasite drag from the airframe accumulations when flying in icing condition but the blades should stay mainly clear of ice so no Tq increase due to ice accumulation.
Hope this is of interest to those of you in colder climes.