Aceside,

At a minimum you need to specify the number of decks, H17 or S17, redouble rules, the true count, the dealers upcard and the player’s exact two card composition to get an answer to your question.

In practice, most flat betting basic strategy players will not play with a bet size anywhere near the threshold amount so this is all rather academic. If, however, you are counting with a decent spread and your large bet approaches the threshold then you should know what to do. Even if the odds favour hitting you are still going to bust more than 50% of the time. The higher your true count the lower the threshold amount will be so if you are able to memorise those numbers for your local game and apply them correctly then so much the better but it won’t do much for your win rate.