Cahsout? Probably "withdraw" word suits most for your question according to this thread. Well i saw many people doing that. I mean they withdraw money after big winning and keep a fair amount on gambling website so that they can start again with it the next day. I think this idea is wise enough for those who aren't professional but do gambling for entertainment. Because as you said, amount has high possibility to losse due to frustration or aiming even bigger amount to win. Although a responsible gambler always control his frustration, emotions and his mind, while gambling.
It is better to withdraw their winnings rather than use them to continue gambling because they cannot double their winnings. By withdrawing their winnings, they can enjoy them with friends or family. After getting their big win, they can return to gambling after taking a few days to de-escalate. And it is also a form of our responsibility towards ourselves to use the winning money to celebrate with the people closest to us. We must be able to be responsible gamblers to avoid selfishness and the desire to continue gambling because we want an even bigger win. It is wise to withdraw the winnings and rest for a while rather than lose all the money if we continue gambling.