Scott's main concern at the very end

So far all odds have been against them; Freezing weather that never reached above -18 degrees, snowblizzards, their ponies died and their machinery broke down leaving them to continue on foot with very little food.

Scott did not think they could hope for better conditions any time soon. He believed they would stick to the end, weak or not, knowing that the end wasn't far away.

His main concern where that they wouldn't make it back home alive.