How feasible is it to move save files?

I have a forever save that I play rotationally in and I’ve been thinking about starting a fresh save. But I don’t want to start all over again. I want to take all of my like 15~ish sims family’s that I play and their lots and move them all to a new save so I can have all of the bugs that are fixed for new saves only fixed and have the updated npcs like the goths (I know I can just drop the updated npcs off of the gallery but I would rather just start a new save with them.)

A lot of my rotational families are related to each other and they all have relationship bars with each other, would I lose all of that if I uploaded all of them to my account and then dropped them in a new save? If I have to sacrifice everything except for their skills and traits I don’t think it’s worth the effort.

Thanks in advance!