The downside of a vegan diet is energy density and nutrient availability. It can be done, and it's about what I figured you were aiming for. You'll have to be real particular about how much of what you plant to make sure you're not giving yourself any nutrient deficiencies (Scurvy anyone? Rickets?) as you go along.
Caloric intake is also going to be a challenge on a vegan diet. You're going to be burning a LOT of calories to perform all the labor required, which means a LOT more plants which means a LOT more field space. Pigs, rabbits, and chickens are the easy way around that as none of them require the huge amount of pasture that cows and sheep will call for.
Reading through the Wiki you posted a few things come to mind:
1: The basic concept groks fine, but their claims are pretty extraordinary (100% fertility improvement? 200% to 600% more food per square meter?) If those numbers were accurate then every farmer and their cousin would be doing it and making 200%-600% more yields.
2: There are a lot of marketing buzz words in there that always raise red flags. Why do my plants need synergy?
3: Even the basic write up calls for 60% of the land to be used for nothing but composting material and 30%-40% for usable food. Right there you're needing double the acreage which puts you back at zero if you're actually getting 200%+ greater yields. You're also going to need to factor in a bee hive or some sort of local polenator for your fields. Pest control will be a challenge but is just another habitat you'll have to figure into the plan.
4: The amount of labor involved would require a LOT of calories again which means a LOT more food. Meat needs to be on the menu.
Like I said, the system sounds plausable but those claims and the space allocation sound off. Being in your geographical area, a greenhouse would be a good plan as many plants that provide things like Vitamin C need hotter weather. Your greenhouse will need full spectrum lighting and active ventilation. Being married to a botanist I've learned a few things about NOT cooking your plants to death in summer and how airflow is important.
It'll definately be an adventure to say the least! I would heavily recommend rethinking the vegan path and look at rabbits and pigs at the least. Those take up almost no real estate and can be fed on the food scraps from your vegetables. The waste is also a good fertilizer source other than your outhouse.
Also, back to the OP, an outhouse with a shower is really nice. An on demand propane heater works well and your only power needs would be some lighting and exhaust fan. Just make sure to put in a way to secure water to the heater and blow air through it before it freezes. There's no way to insulate those and have them still functional. I've tried...
