Since my last update, I finished cutting out the second story walls and floor. It took about a week of nights in the garage after the kids were asleep to paint and add the windows.
Thursday night, I was finally ready to assemble. I glued and clamped up the ground floor. First problem - my sliding doors are 1/8" but the wood from the kit was just shy of 1/4" so the upper track I added to hold the doors in place, snapped off when the doors overlapped to open. I'm going to replace two of the four panels with 3/32" and that should give enough room for everything to move smoothly. The big disaster came the next morning. The glue didn't hold. It cracked when I moved it and one wall fell down and another was disconnected.
I assumed I didn't clamp well enough, so for the second floor, I clamped the heck out of it on Friday night. I used almost every clamp we had. But come Saturday, despite being super clamped, the long wall was only connected to the floor a quarter of the length. After some Giant tears, I read the back of the wood glue bottle, and it recommends 45 degrees or higher. It was definitely closer to 40 degrees in the garage, so I think it was too cold for the glue to set properly. Tonight, I brought both floors inside and am praying the warmer temperature will set the glue properly this time.
At this point I figured I would be a lot further along. I'm not sure I'll finish in time, but I haven't thrown in the towel yet.