Mine will be a lean to next to the corn crib/garage. It will have two doors one to the outside and one to the crib. Crib has large doors and windows to keep the air flowing.
Plan on collecting rain for water that will be connected to water storage in greenhouse and will be erecting a small windmill that will produce electricity to power that structure and the log cabin/guest house.<<<
Sounds like it will work, you will be able to use the air of both and avoid that sudden fall in the temperatures.
LOL, one of these days you will discover that you want one attached to the house, it is wonderful to just walk into it, for a few minutes.
OK, I will admit that I could live in a greenhouse, have no need of a fancy ‘modern’ place.
I have a room with windows on the south and west attached to the house. Not enough room so I’m building the greenhouse.