That's a beautiful place. I'd love to see more pictures of the old schoolhouse if you don't mind sharing. Thanks for posting the pictures as they helped me understand your constraints.
Those photos do clarify why you don't want a deep stove, and I second the suggestion of making a cardboard template of the stove and putting it where it needs to go. Consider the hearth requirements and clearances, too, and live with it for a bit to see if you want to use that location. It looks good for convecting heat upstairs [perhaps even too good if you're wanting the heat to stay downstairs], but you want to have realistic expectations for using the space.
I saw that others commented on your twelve foot ceilings, but I thought I'd reiterate that those high ceilings give you the cubic footage equivalent of having eighteen hundred square feet just downstairs rather than the actual twelve hundred. The Drolet Deco Alto looks to be a good stove, and it's got a decent size to it, but according to Drolet's own website, they only rate it to heat thirteen hundred fifty square feet in Ohio. If you consider that that is assuming insulated space, and your space lacks insulation, you said, you'd need to know going into things that you would be getting an undersized stove.
An undersized stove may be the best solution for taking the chill off which you mentioned as a goal in the last post you made. Your earlier posts mentioned wanting to heat overnight or while you were away, so that's probably why earlier posters were pushing you to go larger. The size of the firebox does a lot to determine how long you can heat, but the harder you have to push the stove to heat an oversized space, the shorter the burn times will be. It won't be providing meaningful heat all night during a cold snap in the dead of winter, but it would add BTU's to the envelope with an overnight load and give your heat pump a break. The heat pump could then warm things in the morning hours till you get the stove stoked again.