One thing that could help would be to buy some bundles of fire resistant batt insulation. Before you bug out, pack the insulation around the safes. When I was 13, we had our double wide trailer burn to the ground. The last part to burn was the master bedroom. The only things to survive were some pictures in the middle of a packed tall file cabinet and a small silk purse (that
my grandpa gave my grandma) in the center drawer of a large dresser.