edonil wanted the actual math:
1 Silent One uses North Wind with Rasputina in range of the effect. Rasputina gains +3" of range on Decembers curse (13") then also gains +3" range on Ice Mirror (9")
13" + 9" = 22"
You also gain the base size of the model, as you don't have to be completely within range for Ice Mirrors, iirc, so really it's more like 23"-24" range, but at the same time, there is no CTRL range measuring in this game (unlike WarmaHordes) so it's rather difficult to get the full range on this combo.
You only need 1 Silent One, but you would benefit from having a second Silent One to Ice Mirror through, as a normal Ice Mirror target gives Rasputina a health -Ca penalty...
Rasputina needs to be within range of the Northwind.
Anything I missed?