I've never had the experience of having a withdrawal blocked, because I believe that after two "generous" wins it's time to change casinos or simply stop playing. Even if you make withdrawals, it's likely that luck won't last forever.
So, I prefer to sleep peacefully, knowing that I "did my duty for the day" than to try new games and end up losing the day.
But, if something like that happened to me, I would stop playing (as I already do) or I would change to another casino, if I need to make a small contribution with part of the profits I made at the first casino.
I understand that casinos need to have some control/security and check some game patterns after many consecutive wins, but this creates a lot of temptation for us to keep playing. So the best thing is to "go somewhere else" where you won't be thinking about all that money sitting around.