Let’s see about that shall we?
The only pertinent concern for comet ISON is on Jan 14 when we will pass through remnants of its incoming tail. That is the dust which was blown off during its inbound journey and was sufficiently slowed by the solar wind to still be in the vicinity of earth on Jan 14. Ergo, the particles must be small enough for the force of the solar wind to have counter-balanced its incoming speed -which was very high. So anything encountered on Jan 14 will be incredibly small, likely microscopic, on a molecular scale. Anything larger, particularly anything large enough to become a bolide is too large to have been decelerated by the solar wind to still be in our orbital neighborhood.
At its closest approach on Dec 26 comet ISON will be 40 million miles from earth and above the solar plane heading into interstellar space at a high rate of speed.
As I understand it, there is no more Comet Ison. There are I nly the pieces formerly known as Comet Ison. If this is not so my post is inoperative. If there are only pieces left, all former predictions of the trajectory are inoperative.