And here is a stab at the timing.
There is a lot of spare time in Ushuaia. I am sure they tried, but failed to get to Antarctica. The weather looks like it sucked. No sunshine.
CHATEAU, my previous information on flights from PUERTO MONTT to PUNTA ARENAS was apparently for a weekday and not valid for a Saturday. The Saturday flights are:
LAN 993 leaves PMC 0920 arrives PUQ 1130
LAN 997 leaves PMC 1100 arrives PUQ 1310
If I follow your increments for the PUNTA ARENA tasks, then teams that make the first flight will be back to the Punta Arenas airport well before the scheduled 1400 nonstop flight to USHUAIA. Teams that don't make the first flight are in serious trouble. Since Charla/Mirna are about an hour away from Puerto Montt airport and leaving the pitstop somewhere around 8am, it's going to be tight for them and also for the Guidos.