Thanks for all of your comments. I'm actually attaching the Primrose to a Glencroft. My original plan was to modify the Primrose to add a taller second floor, but after mocking it up in cardboard, I realized I don't yet have the skill to achieve my vision, so I have altered my vision a bit. The Primrose will be attached to the right side and will be the kitchen, the dining room will be the narrow room, and I have enlarged the door between the two rooms into an arch so they are connected but still separate. I didn't like the stairs ending in the bedroom, which is why I wanted a second floor in the Primrose, but have resigned myself to that arrangement.
I didn't find this forum until after I had finished most of the construction, but I've learned a lot from it now that I've found it!