>>280083003
>>280083036

>Was it explained how the Z warriors survived against them before Goku came back to Earth?

>so we can assume Goku made it back just in time before Fureeza started killing everyone.

Goku was about to teleport until he felt Trunks's KI and when Freeza and Cold were dead, he just figured he could take his time. In the Trunks's timeline, he teleported at the same time the soldiers took of for their 'kill the humans' mission in.