It doesn't really look like a hydrohut death to me either.....usually the entire plant turns lemon yellow and then just folds.....I think the issue is your ph.

Your question as to whethere they will last until finish is unknown. Poor conditions create unhealthy plants. Yours are obviously not healthy. Unhealthy plants tend to develop disease such as root rot etc....which can destroy your plant with 48-72 hours.

That's why growers like Stinky and myself don't slide along praying things will hold "just a bit longer" (because I've lost that game more than once) but try to make sure that plant doesn't GET into a situation where illness becomes much more likely.