You can use larger spaces than 16x16, but the accuracy of location (and consequently, of everything) will be lost. still, 600x600 I don’t know if it would even load.
Again, everything can be faked, as long as you think it through. Why don’t we make the opposite exercise? Let us know where you feel the “faked” environment wasn’t convincing enough, and perhaps someone can help you disguise it.
I found this thread, its recent and its the same topic. Take a look at it.