Depends on Natural draft chimney or power/direct vent option.
I have run mine at 50-60 degree days without any problem or the fire going out, it's an internal brick chimney about 35-40' tall thru the middle of the house from the basement and above the roof line 6'.
Also, on my other stove I have a direct/power vent, that can pretty much run any time/any temp, it is a constant draw on the stove and not temperature dependent. So, that's another consideration.
Hopper size - Depends on the design. Most of the hoppers hold 80-100#, some larger stoves will hold more (150-200#'s) and It depends on how hot you are running it. I would think most small-med stoves on here are running the 40-60#/day when really cold (0-25 degrees), so depending on your set temperatures, you can go 1-3 days without filling the stove. Some of the larger stoves/Boilers, people are using 80-120#+/day.
On Idle/Pilot mode when no heat is required, you can back it down to about 1#/hr, so 24#/day, you could get 3-4+ days without refueling.
You still have to empty the ashes. Figure about 8-10% ash. So, 100# of coal will produce 10lbs of ash. Each stove has different size ash pans also.
Hope that helps.