From everything I can tell Napoleon felt things were still generally on plan at this point despite some unexpected retreats from the Russians. Did Napoleon expect to lose almost half a million men to attrition, raids, and logistics maintenance from the outset?
Far from it, those half million men "missing" are simply troops that were dedicated to the protection of supply lines. Since Napoleon was driving himself into enemy territory, he needs soldiers to protect the supply lines that would get food, ammo, and other necessities. Although it must be noted that most of these half million men were from the "allies" that Napoleon had made, such as from Austria, Prussia, the Confederation of the Rhine, etc. His main battle troops were French and German soldiers under command of his best or most daring commanders.