Yes. The approach to using a grid for drawing is intended to achieve an image as accurately as possible within your drawing. This means that the measurements matter, so the page should be the same size. This will make the process of creating a grid on both the reference image and drawing paper easier. If the pages are the same size, then the measurements used to create a grid on one of the pages can be easily transferred onto the other. This will result in an accurate number of blocks that will correspond with one another between the drawing paper and the reference image. This can also be created using a digital device as well, which means that you can create the same size image on your device as your drawing paper.