I’m wondering this too. Far as I can tell, the larger fire fuels seem to burn for way longer. My approach is to keep a variety of papery tinder, splintered wood, heavy sticks, planks, and logs. I then burn bigger or smaller items depending on how much I need to cook. logic being to burn something that only keeps a fire going as long as I need it.
I haven’t bothered lighting a fire just to stay warm overnight, as the blankets and other bedding materials are warm enough. My longest-living survivor Zach hasn’t made it to winter yet, so I may change my tune in a season.
You don’t really need to keep your house warm. If you’re having problems with cold temperature, wear some blankets before starting crafting or reading and always keep at least one blanket on your bed on the tile you want to sleep on (you’ll automatically use it to warm up but never to overheat).
If you’re using fire to cook and provide light, then yeah - fireplaces and wood stoves are both good. They prevent the fire from growing too much (and thus burning things too fast), from spreading and from producing smoke.
It would be interesting if heat could sort of spread, so if you had a fireplace in an enclosed place, if the fire kept burning, it would start to heat up the entire area. It’d be a very useful and interesting mechanic.
It’s kind of exploity, but you only need fire to start crafting or reading, it doesn’t need to continue burning the whole time. So you can cut a 2x4 into 12 skewers, light one on fire, and then use batch crafting to make 20 meat jerky or whatever.
Similarly, if you’re reading an advanced book that takes, say, an hour for your character to gain experience from, you can light a skewer, read for an hour, automatically stop because it’s too dark to see, light a skewer, etc. Depending on how long your book takes to read, this may get you way more reading time than just lighting the 2x4.
Edit: Just realized this was kind of off-topic. On the topic of warmth, it’s better just to wear a lot of clothes. You can make warm undergarments out of rags using Tailoring, and wear warm outer-layers like a trench coat. A balaclava and bandana will help keep your face warm.