I heat our house 100% with an indoor wood furnace. Heats all our hot water too. Burn time has never been an issue. Easily goes 8-12 hours on one load if turned down and the wood is big-rounds and not thin stuff that has been split to death. We get temps down to -30 on rare winter days. Most of the winter season is more like 15-30 F above.
Our house is a big old farm house. 1/2 built in 1820 and the the 1/2 in 1995 (I never quite finished it).
We keep the house 70F when anyone is awake. At night - I load it around 11:00 PM and turn the thermostat down to 60. 6-7 AM in the morning the fire is still fine. Just throw in some more wood and turn the thermostat up.
There is a big difference in burn rate depending on temps. When it's in the 20s outside (F), I often find the furnace with a 1/4 of the wood left in the morning. If it's 0 F or below - I'll a bank of coals in the morning. Plenty for the fire to take right off once I throw some fresh wood in.
When I got it it was the biggest and most rugged furnace I could find. Myers Woodchuck model 4000. Made by Myers Farm Equipment. Hot air distribution.
I have a 2nd wood furnace in my barn. Smaller, crude, and not blower. Just convection. Thermocontrol 500. Made in Cobleskill, NY (20 miles from were I live). It heats my entire 3 story barn and workshop. No thermostat; just a bi-metal air-take door control. It too never burns out. I load it once at night and once in the morning, and once mid-day when I'm not working in the shop and it's turned down. When I turn it up it eats a lot of wood.