As a previous hiker and hammock camper, I can say without a doubt that it is entirely possible to camp in comfort without all these gadgets and heaters. Now, if you want to use them, fine. But I don’t feel they are required, and I’ve camped down into the single digit temps.
You just need to dress appropriately and in layers. As you get active and warm up, you can strip layers off. When you sit down after dinner, put the layers back on. For sleeping, something like long-johns will help, but just make sure your quilts or sleeping bags are rated for the temps. All my stuff is goose down. Yep, it ain’t cheap, but it’s soooo comfy. Synthetic works great too.I sleep with socks and a balaclava. I usually sleep really well when it’s really cold - though I tend to have to get up a few times to water the grass, which I think is an artifact of the slightly higher metabolism keeping me warm.
My point is that I recommend you do some research on what is possible without all the heaters, etc, first - as most people think it’s a requirement. I really look at a heater as a luxury. JMHO
As a side note, I recently purchase a Jackery and I’m gonna try a small (200W) electric heater on my next winter trip. However, I’ll only run it for like 30 minutes prior to waking up, just to heat up the car. If it doesn’t work, no loss. I’ve camped for two winters without one.