Double the length doubles the area, then you need double thickness for strength, so every sheet would be doubled. That's if you do everything double, but with more thought and adjustment to the structure, you might be able to save some weight/thickness in some areas.

if you started with a 1ft square, which is 1 sq ft, double would make it a 2ft square, which is 4 sq ft, then you need two for double thickness = 8 sq ft.

Basically, wing area follows a square function, and mass follows a cube function, so wing loading will always go up as you increase in size.