I think you have a point asking "Where to draw the line?" Obviously I don't have a simple answer to this question because it would just be an arbitrary line to draw. Also this matter can't be discussed with Enyas wealth in mind alone but with wealth in general.

I think to answer this question it would be necessary to know who (as in "the richest 0.x % ) would have to abandon how much of their wealth to reach a certain goal for the poorest x % and as long as we can agree that the benefit outweighs the cost (maybe even in a significant manner to "allow" a certain amount of inequality) it is save to draw the line there.

I'm speculating now, but maybe we would come to the conclusion that it would only take a little amount of wealth of the richest few people to lift the poorest of the poorest out of severe hunger. I think we could agree that this would be very reasonable because the benefit would greatly outweigh the cost. Maybe even providing basic housing to all people who need it would cost only a neglectable number of people some of their huge wealth. This could also be a possible line then.

So as you see I'd try to draw a line using some utilitarianistic criteria.