I'll give you some suggestion.
If having 250 big blinds (BB) will put you out of your comfort zone, leave the table. If you are feeling good, playing good, and can play 250 BBs comfortably, then keep playing.
If you are on a strict bankroll management, then maybe sitting out your next big blind is the proper play, but if you are on a dream table where everyone at the table is playing poorly, then keep playing. Cash game is about making the most EV+ plays at every moment. If you start to reach EV- decisions it is time to either take a break or find a different table.
It is the same scenario if you are down -250 BBs. If you are facing a tough table and down 250 BBs, you should probably move on.