empty neighborhood - long, epic life

I'm playing Sims 4 on console in epic mode. I extended the lives of the sims several times and reached the point where almost all the sims in the area died. 

I tried to save the family to the gallery and download it using a new save game, but unfortunately all the equipment (including all collections) is lost.

Is there any way to make a family of sims with all their equipment available in the gallery?Alternatively, is there any other way to transfer the family to a new save game with all the families originally included in the game?

thanks for your help!