1. Yes its difficult and also depends upon what kind of traffic conditions are en route to Rohtang. None the less Manali to Leh is 2 days route, so breaks can be planned as situation arises. 2. See Plan B, Yes fuel will be a big issue, therefore additional tankful fuel will be required and thats where the problem is, although there are places where we can get fuel from shops, but then its need to think upon how we can redo the plan to add fueling points.