I bought a BK Princess and had it installed Sept 2022. I was told it would heat my house no problem. My home is 1640 sq ft on the main floor and the same for my finished basement.
So, 2x 1640 = 3280 sq.ft.? There are many web sites which will help you estimate your heat load, although simply looking at your traditional heating fuel costs / usage is probably more accurate. A Princess holds 500k - 700k BTU of fuel, depending on species, and allows you to dish that out over a range of perhaps 6 to 30 hours, if your setup is working properly.
It seems likely that 3200 sq.ft. in Ontario probably creates a heat load requiring more than the ~20k BTU/hr you're going to get from 3 cubic feet of wood dialed down to a 30 hour burn time. I'd expect finding the dial setting that corresponds to a 12 hour reload cycle would work much better.
The brochure says is can heat up to 30 hours on one load but I can’t get that stove to run on the lowest it can without going out for more then 10 hours in 10C weather.
Many members of this forum are repeatedly hitting the advertised burn times, and in fact up to 20% longer than advertised times, on all of these BK models. I'm hitting up to 36 hours on my Ashford 30.1's, and they're about 10% smaller than your Princess, based on the same tech.
There are three things required to hit these long burn times:
1. Very dry wood.
2. Draft near 0.05"WC (or higher) at high burn.
3. Finding the "stall point" on your dial.
Dry wood is self-explanatory, most of us follow a rule of 3+ summers split and stacked under a roof in open air, although we have two members here hitting very low MC%'s in just one summer using clear plastic tarp solar kilns.
Low draft will cause a stove to stall, when trying to hit very long burn times. This is because the heat output is so low, and the efficiency of the stove is so high, that very little heat is going up the flue. Cool flues don't provide a lot of draft, compared to a hot flue, and so it's very easy to stall the stove.
Stall point is the dial setting where you will put the fire out on a BK, even with a good chimney and dry wood. All BK's can be turned down past their stall point, call it a safety feature if you want. Find and mark the location on your dial where this happens, once the other two issues are nailed down. It helps to use a piece of tape that you can move around as you find this point on successive loads.
Plus, if I want to have my home at 22C, I have to burn it at 600F for 24 hours before I can lower it to 400F and maintain temperature.
That's a function of your home, not the stove. BK's aren't magic, they're just 3 cubic foot boxes filed with burning fuel. Any similarly-sized stove s going to work the same, in this regard.
I originally wanted to pay the extra money to get the biggest one, but I was talked out of it and assured the princess would keep my house toasty. Wish I had that one now.
Was an 8" flue an option for you? If so, I suppose you could always trade up to the King, but the house is still the same.
So I’d put the extra money in unless you have a good deal on 2 stoves. One for each end.
This is what I did, two BK30's, and I was able to work a good deal by buying two at a time. I'm way farther south, but heating a space almost exactly double yours. One stove is loaded once per day, and set for a 24-hour burn cycle. The other is usually loaded twice per day, correspondingly set to a 12-hour burn cycle, although we'll also run a third load through it at wide-open throttle on very cold days.
One final note on draft, WRT "wide open throttle". I said above you want 0.05"WC or higher to hit the longest burn times. This is just an indicator that when things run real cool and slow, you probably have enough draft to not stall. It's really not the best indicator, but it's the one we have from the manufacturer, so it's what we use. That said, draft that's too strong will affect your ability to comfortably run full loads at wide-open throttle. If your chimney sucks 0.20"WC on high when hot, then you're going to want either a key damper or to run your "high" loads with the thermostat turned down a few degrees.