That was my original position. That they should wait it out.
But then I read opinions of medical consultants, painting a gloomy description of the potential dangers of 4 months in that cave.
They will be prone to disease and infection as time goes on. It will be constantly wet and very hard to keep the area clean of human waste, and refuse, over a 4 month period. So bacteria and disease will be surrounding them.
And there may be no way to connect with them from the outside for months at a time. No new supplies, no new support, once the floods begin. So they will be depressed, anxious, frightened and weak.
And there may be severe breathing problems, as the air may thin and even be toxic over time.
I think that they are right in trying to make the journey...
At this point all the options seem pretty rubbish :-/