I don't consider it insane. I actually like the idea. Think of the added warmth you will get in the bedroom when opening one of your windows. Also, imagine replacing one of your windows with a door so you can walk right out of your bedroom into your greenhouse.
I actually wanted to build a greenhouse on the deck outside our dining room French doors. Like you, the wall of the dining room would have been the north wall. Unfortunately, a contractor told me the deck would not support the added enclosed greenhouse structure.
