How about using coal in the stove VS wood.
I switched last winter to coal. I was able to go 12 to 24 hours between loading's.
Also way cheaper. I only burned just under two tons of coal for a cost of under $100.
If I burn firewood, The cost is $1500 to $2000 a winter.
I like you got sick of loading the stove every 3 to 4 hours, waking up cold, ect.
About pellet stoves.
Find a stove you like, and see how many amps the blower motor needs. Then you can calculate from there.
If you really want to use a pellet stove, here is one that has a hookup for 12 battery power as a backup. The literature should tell the power needs.
This site says his stove uses 9.33 amps at 12 volt.
100 watts at 120 volt.