Can my unwrapped UV be scaled outside of the UV grid? So I have UV unwrapped an object, and everything fits inside the UV grid as it should. But why should it remain within the UV grid? 

Do I need to keep it within bounds or can I scale it outside the grid?
If you extend the UV grid the size of the texture will change inverse proportionally. If you make the UVs larger the texture will get smaller and start repeating itself.