You have a machine that can do it so I hope it works out. I learned of a another type of greenhouse similar to a walipini that uses solar energy --natural not with solar panels. A guy from China has built one for commercial use in Alberta. He says this is a design that is common in China. I do not understand why he doesn't heat it, but perhaps it has to do with reducing his overhead. It involves building a thick clay wall on the north side, and then having a double plastic wall on the south side. There is an air space between the plastic, which insulates the interior from the cold. The clay wall absorbs the heat from the sun and radiates it into the greenhouse atmosphere.

I how the double plastic will work to keep out the cold because, when I was a kid in northern British Columbia, we had plastic windows. This was common as people would use plastic until they could afford to buy real windows. I should write a post about that lol. Anyway a sheet of window plastic on the inside and a sheet on the outside of the house with a dead air space between them. It kept us toasty inside.

If I were to make something like this, I would want to include a heat pump to keep the inside of the shelter a minimum temp of 60 F. Alternately, an electric heater with a solar panel could also work. I don't know though---would this structure need extra heating? Probably not where you are, but my current greenhouse gets to be -50 inside when it is -50 outside.