I don't knock what the Dervaes Family does, they do a terrific job with gardening and being frugal.
I would only caution those that might think the Dervaes are "self-sufficient" at that location. To the contrary, it appears that they are VERY reliant on the municipal water supply.
I just think it might be a bit of a misrepresentation if they are marketing their family as "homesteaders".
It seems to be more accurate that they are a very successful "commercial organic farm".
Again, I applaud what they do.
But, related strictly to "survival", their operation is very vulnerable to a shortage of (or lack of) WATER; if there were an interruption in the "city" water supply.