If the road is clear of snow, one can park nearer Fall River Reservoir with a car that has moderate clearance, e.g., an Outback. For AT skiing, my advice is to travel around the reservoir on the north side, both uphill and downhill. The open terrain just northwest of the reservoir, between 11k-11.2k is very steep, an ice ax (at least) and perhaps crampons being needed for the uphill portion. But cutting through the dense trees on the north side, on a double fall line, has its own set of difficulties, both up and down. But I would propose cutting through those trees on the north side of the reservoir to 11,200, then traversing northwest to regain the track.