I completely agree. I'm also an old TLD player and I just kept adding firewood figuring that as long as I get enough hours on the fire combined to last until morning, I'd be good. I also thought that as long as Will had <numberOfHours> worth of firewood gathered, that would be good enough since IRL you can not simply dump all the firewood at the fire in one go and expect it to last that much longer. So I added some twigs, waited a bit, boiled some water, added some more twigs, waited around 1 hr IRL while preparing my dinner, finally I added about 4 hours in one go since half the night had passed and that was what I were able to gather given the completely dark environment outside the cave.
A little textual tutorial hint along the following lines would have helped:
"Gather 9 hrs of firewood while there's still some daylight left, then put it all on the fire until there is 9 hours left before the fire goes out." For new players, this is a much better alternative than first spending 1hr IRL figuring out what is the right procedure for one of the very first challenges in the game.
Other than that, I'm enjoying it tremendously!