>>2628857Assuming this isn't a shitpost.
Thermal layers, and you want the outer layer to be looser fitting, by dressing in layers you can strip down if you need to correct for temperature fluctuations.
A good all weather sleeping bag, bedroll and a good tent, this will protect you from the wind, the body will be able to regulate temperature, with next step.
High fat, calorie rich foods. The Inuit in my native Canada eat blubber for a reason, anything the body does not store as fat, gets vented through the skin in the form of energy expenditure/warmth. As long as the outer shell covering is good at insulating, the core body temperature will be sufficient in creating enough warmth to deal with sub zero temperatures, as long as your shelter is able to make a differential temperature to the outside, you will remain tolerably warm.