My husband and I had a one-year-old and a three-year-old. We paid contractors to do the excavation, pour the footer and lay the block, and then we did all the rest of the work ourselves with help from friends and family and "help" from our kids.
It was a once-in-a-lifetime project, exhausting, exhilarating, mud-covered, sweat-soaked, crazy. I'm so glad we did it. I would never do it again. Actually we are building a second structure now but with bigger kids, not toddlers, and much more slowly.
The easiest way to go off-grid is to need as little electricity as possible.