Max Bankroll for Max Variance

I know that one should expect swings of 100 units, but has anyone actually experienced being down more than 100 based not on poor play but on simple variance (natural swings in any game of chance).

In other words: if someone was to flat bet and count only so that the player/house edge is 0% and played 4 hours per day for months flat betting $1 each time, what would be the most units down at any particular point before things would cycle back down close to zero?

What is the highest number to expect theoretically? (Maximum Bankroll needed to allow for natural swings)

What is the highest number that anyone has actually experienced?

Thank you, my hand dealt tests show a variance of 80 over 5800 results but I know it must go higher.