The main difference is the stove you use in it. For a winter tent, you need a continuous burning stove or gas heat exchanger. For a sauna, you need a high-intensity stove.
Our tent saunas MORZH are universal. The awning is made of a three-layer quilted cloth “Thermostitch”consisting of Oxford 240 fabric, Siberia insulation and light strong Tafet fabric with reinforcing weaving.
Due to the three-layer awning, the tent perfectly retains heat, which makes it comfortable for living in winter. And this tent is the hottest one in the mobile sauna mode.