I think the main issue is what people consider "an overnight burn". I believe different people have vastly different definitions of what this is.
THere's 2 extremes to the definition:
Some consider a bed of coals and a 200* stove a successful over night burn.
Some consider it successful only if your house is still 70* or above in the morning.
And as you might suspect, some think anywhere in between or a mix of the 2. Some people have houses that a 200* stove and a bed of coals will keep warm. Others have huge drafty homes and unless your stove is running med-to-full tilt, it's not gonna keep the house warm. It really comes down to how well the stove is sized for your home. If you have a huge drafty house, almost no single stove is gonna do it on those cold windy nights.
If you were to call an HVAC company in to install a new central heating system in your home, they would do a complete workup on your's homes BTU loss, heating degree days for your location, number of windows, doors, sqft, construction type, exposed wall surface area....etc.....and that gets them a good accurate estimate of what size heating system (in BTU output) they need to install. I think the same should be done at least in part for a stove installation, or at least know where your stove is in comparison to your homes BTU loss. And again, once you get into large homes, the stove choices really start dwindling down, only a select few are rate at 100,000+ btu's, and that's only at full tilt, during an overnight burn it's running at probably 20% of the rated BTU output. On the plus side, a stove is putting out constant heat unlike a forced air furnace which comes on and blows full tilt and shuts off. So 20,000btu's for an hour is very close to 120,000 btu's for 10 minutes.
I have a 2500sqft home with 28' ceilings, it's newer (late 90's) but the builder didn't take any time to seal anything. In some areas it's almost drafty even. On a 25 degree day I can load up my North Star at 11pm and the house is still 68-70 or so at 7am. On a windy 10 degree day like we've have the last 2-3 days ,it just doesn't happen, the stove acts the same, but since the home loses BTU's at a much quicker rate, around 3-4am the temp in the home starts dropping,quickly. On those days, I don't even try, I still load at 11, but I don't try to build up coals or wait until the most opportune time to load or anything like I might on a 25 degree day. I just throw some wood in, let it get going and close off the air. On a 25 degree day I might spent alot more time to build up to the overnight burn to help it last longer and be more productive.
With that, I can state that my objective in the context of "overnight burns", is if I can keep the propane from burning in the AM to put the house back to temperature, if that's possible with my stove in my house for a given outside temperature and wind conditions, then I try really hard to do that. But I know enough to know, on a windy 5 degree night, it just not gonna happen no matter what I do, so I don't really try.
At any rate, yes, with most newer stoves and dry wood, it should not be any issue to have a bed of hot coals and a 200* stove after 8-10 hours. Weather that's keeping your house warm is a completely different story.
. . . however after awhile you kind of get used to temps in the house and in my case I find myself waking up during the night occasionally to throw in a few splits . . . which means I'll have even more coals . . . but honestly, if I don't wake up during the night I often find I have enough coals to get the fire restarted easily enough . . . and if I don't wake up during the night and find the fire is actually dead and the oil boiler has kicked on . . . it's not a big deal . . . the woodstove kept the place heated most of the night so what little oil I used is not a big deal.
