I've said it before but I gather you don't have time to read the forum all that often so I'll recap. If you burn the stove low enough to get 30 hrs. out of a load, it must be pretty warm out because the heat output over that time from the BK will be very low. My firebox is only half the size but I can have a few coals left at 24 hrs. if I cut the air down. And even though the stove top is barely warm, my leaky house with uninsulated walls has only dropped a few degrees room temp because it's not that cold outside. So instead of loading onto the coals and burning the load in for 30 minutes with the air wide open, which is stated in the manual and many BK owners here say you must do, I will instead shove the remaining coals to the back and light a top-down fire, have no smoke out of the stack while the stove comes up to temp, and not burn up wood unnecessarily in the process. Lighting a top-down fire is easy for me so I don't place a high priority on always having a coal bed to load onto. On my 16' liner, with the stove rear-vented and temps as high as the upper 50s outside, I can burn at any air setting/draft strength I want, with no smoke smell or smoke roll-out when I open the door (side loader, so it's less prone.)
My little stove won't heat 2200 sq.ft. but other cat stoves will. No, most of them won't have the Wife Approval Factor of a white enamel stove (which I would also find attractive) but the WAF isn't the top priority for me either..it's all about stove quality, engineering and performance. And I don't care if occasional visitors are impressed with the look of my stove or not. My rear-vented into the fireplace setup has
got to look better than a big ol' ugly black pipe dominating the space anyway.
Kind of a threadjack here but this topic has been flogged to death so many times with no resolution that BKVP doesn't even show up anymore. I think aaronk25 may be onto something though..
The Ks would heat the heck out of that space, and you would feel the radiation of the stove within line-of-sight of the stove, within most of that room..a help if some of that heat is going upstairs, and the downstairs might be a couple degrees cooler. It's gonna depend how much heat you allow to go upstairs. You don't have another stove up there, I take it? I moderate the heat going to the bedroom by how far I have that door open. Ash grate=High priority for me. That and the big window is why I went from the Fireview to the Ks.
A 2x4' opening would allow a huge amount of warm air upstairs. You might want to go with a bigger stove if cutting your heat bill is a consideration.