Go to Edit town and save any household you want to transfer. They will appear in the library. This can be done to individual lots too, but if you want to save a household separately from the house, you will have to evict the family (they will the corner), save them and then click on the lot to save the lot itself.
It's tedious if you have lots and lots of stuff you want to transfer over, but it may be worth it. I suggest you check out Hidden Spring's geography and landscape as well as overall lot size before doing so. This way you'll know which lot you can transfer directly without having to place lot size space, or whatever they are called.
Have in mind that you will lose any relationship your sims have outside of the household. For example, if a family split up (parents living together, children who are now adults living with their own family), they will lose their family tree. To fix this, you'll need the MasterController mod. I think you can also use another of Twallan's mod (The porter), but I never tried it so I won't be able to give you support on that.