concerning the calculated 83 #'s per day for the DSM 1400, even with my less than optimally sealed house, i can't imagine the weather needed to require that.
we had over 72 hrs. of -25 / -35 F wind chills here already and i burned 60 #'s per 24 hrs. ( putting 20 #'s in the stove every 8 hrs. ) at 525* stove temp. for that period. this was achieved with the intake flap 3/16" open and -.04 WC both MPD's closed to hold it there against the wind.
BUT, i have a small area being heated ( 1250 sf.) and i bought this size stove purposely, expecting NOT to need more than 1/2 it's rating even in the worst case situation, but having excellent reserve capacity if needed.
EDIT. you may have gone alittle far on the equation. i'd go half way back to "187", that would be 57,750 for the DSM 1400 and very realistic i think.
57,750 / 12,500 = 4.62 #'s per hour. i was burning 2.5 's per hr. at 525* during the coldest so i guess i could see putting 2 more pounds an hr. thru it, just not in MY house.