I hope there is an actual answer to this question.
What I'm trying to accomplish over all is to keep the amount of RAM used to a minimum. I'm not too sure about how Unity handles this, and that's question for another forum anyway. I'm wondering is it generally better to create small .blend files and assemble them in the game engine of choice or have one large level and let the game engine handle the level loading.
At the same time I'm also wondering about UV mapping large levels. For example I'm working on a building. Its rather simple single level school. I've build the model no problem. I'm just wondering should I break it down into individual rooms, then reassemble them into the "building" in the game engine of choice? Or even build each room separately and assemble them into another .blend file, as the whole building?
I guess what I'm really asking is: How do large/successful game developers handle large level creation?
I'm sure the answer varies depending on the device your product is aiming for. Lets assume a tablet for now.