I think we three agree that Wellington's intention in case of reverse was to retire towards the north and not the west to maintain communications with the Prussians while covering Holland. Given that the Armies of the Upper and Middle Rhine were about to enter France, Napoleon did not have the luxury for a prolonged campaign in the North unless it promised to inflict massive damage and secure that flank. I doubt he could have achieved that aim, unless he could somehow force Wellington to the west. Therefore I would see that Wellington would do all in his power to ensure a line of retreat to the north.
I have a copy of the Lowe report, courtesy of Peter H. He did indeed find the original and transcribed it. It really doesn't say much that is not addressed in the item in WD that Ron has linked to. If you want a copy, please email me off-line and copy Peter so that we may secure his permission. Regards,
David