Could have tried to reprogram the re-entry sequences so the impacted area took less heat.
The best they could have done, I believe, to increase their chances would have been to dump as much weight as possible. Eject science experiments, suits, food, water, anything to reduce the overall shuttle weight... then pray as they returned.
There was no magical alternative path to keep them safe.
THERE WAS NOTHING THEY COULD DO...............
According to NASA, they do that anyway on every flight.