Regardless of bankroll you will surely get from your cold storage or wallet because if we decide to play gambling we really need money to do that therefore we get money on our pockets and thats the time we use that money to earn money and if you are not lucky enough that amount will lose and you will try to deposit even more to chase your lose.
Well i think this is up to the person, but depositing more can be controlled. If the person know what he is doing, he will plan ahead, put a budget on how much he is willing to put on the bankroll and play with it. Then if bankroll is depleted then the person need to stop playing and come back another day. Smarter people widthraw part of their winnings to save some money while winning. This will enable them to play with only the profit and save the initial bankroll. If ever they lost, they have saved the initial bankroll and actually lost nothing except the time though, i bet the person had enjoyed those times.