1) Buy a good quality double layer hot tent like the Russian Bereg ones and a stove that goes with it.
2) Find the perfect spot innawoods to squat. Something with plenty of water to drink and fish from, with wild edible around and even some game to hunt, ideally. Something far enough from cities so that no people will pass by, but not too far away so that you can still realistically make some supply runs for the things you won't forage/catch/hunt yourself (so, most of the food you're gonna eat since we're larpers).
3) That's literally just it. If a park ranger or whoever finds you and tells you to GTFO, just unpitch your tent and pitch it further away in a more hidden place. Depending on where you live you might even have squatter rights to look forward to.

You can be comfy, hot and sweaty in a Bereg tent in harsh winter conditions. They're literally selling accessories to turn the tent into a sauna lol.
https://youtu.be/vAdc2V4-4qI
https://youtu.be/7A0We7a_ZDo

inb4
>poorfag
>spending ~$1200 in tent+stove
if you can't get to move your ass and save 1k for something that will allow you to live rent free anywhere anytime of the year then you're a lost cause

Just pick fruits or do other farm jobs if you need money for food or to buy the tent in the first place. This is what Forest Anon is doing, but he's taking even more risk than what I'm proposing since he built a shelter and it would suck for him to get kicked out and have to redo everything somewhere else.
https://www.youtube.com/c/ForestAnon

Bereg European Market: https://bereg-ekat.ru/
Bereg American Market: https://hot-tent.com/
There are other cheaper brands like "Luxe tents" but the quality isn't as good as Bereg and they're not double layers so less efficient in winter.
Nortent is an other good brand but probably less bomb proof and not double layer from what I can see.

Please tell me if I'm deluding myself and the problems you would face if you did this, because I'm seriously planning on doing it.