If you are done with the family, restart by all means. Maybe leave this save on the side until you feel up to it.
However, I do think three toddlers is manageable in 4, especially since one with age up soon enough. If it simply isn't your preference, though, you can remove however many kids or cheat the aging. Plus nannies can be great for some relief.
If you do want to attempt to roll with it and still worry about the work with a nanny, I'd consider moving in a grandparent or aunt/uncle to help with the kids. You don't necessarily hear about it much anymore, but it does happen.
