Status Updates From Bird Box (Bird Box, #1)

Just started the novel and read Chapter One. Malorie lives with her two acute-eared children in a run-down, dirty house in some sort of post-apocalyptic world, wearing blindfolds every time they go outside to protect themselves from an unknown threat. On a foggy day, Malorie finally takes the children away from the house forever, to row a boat down the river to an unknown location. Where are they going?