FATMAP difficulty grade
The Northern Twin Valley can provide some epic skiing, not too far from Thredbo, compared to the southerly valley, the vegetation doesn't begin as high here, thus you can expect longer and more consistent fall lines with more open terrain.
As well as that you may get some more vertical too, as this side of the valley seems to hold the snow better than the other valley.
The best way to access this area from Thredbo is to head due north from the top of Merritt's for about a kilometre, out across the top of the North Ramshead Range, then turn to the North East and skin for about 3 kilometres, passing the southerly valley, climbing further on the top then drop in anytime after a significant spur separates the two catchment areas.
From Charlottes Pass, follow the route shown on the map over Stilwell.
Pick a line from the many in this area, take care of possible slides, they have occurred in the area in the past, always assess snow conditions beforehand.