Print box bigger than the printer bed
Are you making a simple box? Or does it have some kind of detail or structure? The photo below exemplifies a structure attached to connectors that have been created outside of Fusion, but you can also use it as an idea to create your own!



Link to OPENSCAD LIBRARY

If you are thinking of cutting into parts, you can also create a kind of male / female (puzzle) in the parts that fit. Something like that ...



Here is some interesting information to study How to design Snap-fit Joints for 3D Printing