One thing that should help is they can take a little break once they get to chamber 3, where the SEALS have set up a base. I think that might be three hours away IIRC.
I'm not sure that taking a break is a good idea. The time constraints are very tight before the rains return, if the boys are panicky stopping is the last thing to do as it lengthens their time in the cave and most important is the quality of the air down there. I know they are trying to improve the air quality but lung trouble could also be massive problem. Once they decide to take a boy out, they need to do as quickly as possible.
I kind of hope they give the boys amnesic drugs if they are bringing them out through those tunnels. Yes, they need them to help but its going to be claustrophobic and frightening as all get out. The less they remember, the better.
Hoping for good news, maybe tonight or in the morning.